Application-level live synchronization across computing platforms including synchronizing co-resident applications to disparate standby destinations and selectively synchronizing some applications and not others

ABSTRACT

An illustrative “Live Synchronization” feature creates and maintains a ready standby “synchronized application” that is available to take over as a failover solution for a “primary” application that operates in a production environment, but will do so on a different computing platform (e.g., physical server, virtual machine, container, etc.), and possibly on a differed kind of computing platform than, the primary. The illustrative system has specialized features and components for discovering and singling out each primary application and identifying and locating its disk image, e.g., VMDK file. The application is Live Synched to the standby/failover application without reference to whether and how other co-resident applications might be treated. The standby/failover destination supporting the synchronized application may be located anywhere, whether in the same data center as the primary or geographically remote or in a private or public cloud setting.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/387,384, filed on Dec. 23, 2015, and entitled “Application-LevelLive Synchronization across Computing Platforms Including SynchronizingCo-Resident Applications to Disparate Standby Destinations andSelectively Synchronizing Some Applications and not Others.” Any and allapplications, if any, for which a foreign or domestic priority claim isidentified in the Application Data Sheet of the present application arehereby incorporated by reference in their entireties under 37 CFR 1.57.Also hereby incorporated by reference herein are U.S. Provisional PatentApplication Ser. No. 62/265,339, filed on Dec. 9, 2015, and U.S. patentapplication Ser. No. 15/365,756, filed on Nov. 30, 2016, both of whichhave the title of “Live Synchronization and Management of VirtualMachines across Computing and Virtualization Platforms and Using LiveSynchronization to Support Disaster Recovery.”

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentand/or the patent disclosure as it appears in the United States Patentand Trademark Office patent file and/or records, but otherwise reservesall copyrights whatsoever.

BACKGROUND

Businesses recognize the commercial value of their data and seekreliable, cost-effective ways to protect the information stored on theircomputer networks while minimizing impact on productivity. A companymight back up critical computing systems such as databases, fileservers, web servers, virtual machines, and so on as part of a daily,weekly, or monthly maintenance schedule. The company may similarlyprotect computing systems used by its employees, such as those used byan accounting department, marketing department, engineering department,and so forth.

SUMMARY

Traditional approaches to block-level storage management usually performbackup operations and other storage management operations at a physicaldisk or logical disk level or for an entire virtual machine, backing updata blocks regardless of which files or applications they are connectedto. For example, an entire disk or logical volume comprising severaldisks may be backed up at the block-level or an entire virtual machineor container may be backed up. This block-level approach tends to yieldspeedier results as compared to file-level storage management. However,a need exists for taking into consideration different levels ofimportance that might attach to the variety of applications that operateon given computing platform, whether the platform is physical orvirtualized.

Applications that are configured and/or operate in a productionenvironment will be referred to herein as “primary” applications.According to the present invention, an illustrative “LiveSynchronization” or “Live Sync” feature creates and maintains a readystandby “synchronized application” that is available on standby to takeover as a failover solution for the primary application, but will do soon a different computing platform (e.g., physical server, virtualmachine, container, etc.), and possibly on a different kind of computingplatform than, the primary. A primary application that is targeted forLive Sync may co-reside on the same computing platform (e.g., physicalserver, virtual machine, container, etc.) as any number of otherapplications. The illustrative system has specialized features andcomponents for discovering and singling out each primary application andidentifying and locating its disk image, e.g., VMDK file. Theapplication is Live Synched to the standby/failover application withoutreference to whether and how the other co-resident applications might betreated. For example, if a virtualized production environment executesthree distinct applications on a virtual machine, a first primaryapplication may be Live Synched to a first failover system (e.g.,another virtual machine) for use in a disaster recovery scenario; thesecond primary application may be Live Synched to another disparatefailover system (e.g., a physical server), likewise for use in disasterrecovery. The third primary application may be considered lower priorityand not subjected to Live Sync; instead, the third primary applicationmay be backed up according to traditional methods, but is not LiveSynched to a standby system, and therefore must be explicitly restoredfrom backup before use. Thus, according to the illustrative embodiments,co-resident applications can be individually Live Synched to disparatestandby destinations while some applications might not be Live Synchedat all. Since the disclosed approach is able to auto-discover eachprimary application and its associated file system, primary data, anddisk image (e.g., VMDK), each application can be treated individually inthe illustrative storage management system. The application-specificLive Synchronization described may be used to support disaster recoveryscenarios, wherein a failure in a primary application triggers thecorresponding synchronized application to take over operations withminimal downtime. The standby/failover destination supporting thesynchronized application may be located anywhere, whether in the samedata center as the primary or geographically remote or in a private orpublic cloud setting.

Application-Level Live Synchronization.

In contrast to the prior art, the illustrative systems performapplication-level synchronization, individually protecting each primaryapplication, instead of Live Synchronization of entire virtual machineswhich may host any number of applications. This individual treatmentprovides flexibility of destination type, such as synchronizing anapplication from a virtual machine to a physical host and vice-versaand/or from one type of host vendor/technology to another type ofvendor/technology, including to/from cloud computing platforms. Theindividualized application-level protection also provides savings indestination standby storage space, network bandwidth, as well asimproved recovery time objectives (“RTO”) for targeted applications thatcarry high importance to the business.

Selectivity.

In addition to the individualized application-level Live Synchronizationthat selects some but not necessarily all primary applications for LiveSync, the illustrative systems further include options foradministrators to even more closely tailor operations to their needs.For example, a system administrator may select only certain source datato be synchronized relative to a certain targeted application. Filteringcriteria include logical volume, hard disk, and/or folders/files. Thisapproach improves system performance by reducing the storage footprintof backups and of the standby copy, reduces network bandwidth, and saveson processing cycles required of the various components. Moreover,certain applications may be selected out, i.e., not Live Synched at all.

Block-Level Continuous Data Replication.

Block-level continuous data replication (“CDR”) from primary to standbydisk image without using intermediary backups and restores providesanother important advantage, because it enables the illustrative systemto keep the standby copy closely mirroring changes in the primary, sothat little or no data is lost when a switchover from primary to standbyis needed. The result is that a given application may be kept in a ready“warm” state at one or more standby/failover destinations, quiteindependent of how the application's co-resident applications and/orprimary storage is treated in case of a failure in the primaryproduction environment. Block-level CDR advantageously enables fastprocessing and sparing transmission, as well as speedy updates of thestandby copy, by using capturing and manipulating only changed blocks,in contrast to more traditional file-level continuous data replication.

Smaller Footprint when One Data Agent Protects Many Applications.

According to the disclosed new architecture of the illustrativeembodiments, one enhanced data agent can protect a number of distinctapplications on one or more computing platforms. This solution greatlyreduces the footprint and installation/management effort associated withtraditional data agents, each of which is individually paired with atarget application and separately with its file system. Instead,according to the illustrative embodiments, a substantial number ofprimary applications can be protected by one enhanced data agent. Insome cases, limited-footprint components are additionally installed onthe primary computing platform and coupled with the targetedapplication/file system, but they have small footprints compared to themultiple data agents and furthermore can be automatically pushed theretoby the enhanced data agent itself as needed. In many systems theillustrative enhanced data agent may co-reside with a media agent on asecondary storage computing device, which means that the enhanced dataagent does not require additional specialized computing hardware. Thedisclosed architecture is especially advantageous in very large datanetworks and data centers, where having one enhanced data agentresponsible for several primary applications can save a great deal ofeffort in installing and maintaining enhanced data agents.

The illustrative application-level Live Sync approach can take a numberof different forms, depending on need and on the nature of the primaryapplications targeted for Live Synchronization. A number of salientcomponents play important roles. First, an enhanced data agent isinstalled on a computing platform other than the one hosting the primaryapplications, in contrast to traditional co-resident data agents.Second, the enhanced data agent establishes communications with theprimary applications' host to discover what applications might beconfigured and/or operating thereon. Third, the enhanced data agent willdetermine whether the auto-discovered applications comprise a respectiveconnector or application programming interface (“API”) or another likeutility to enable the enhanced data agent to perform one or more of thefollowing operations: communicate with the primary application,discover/identify its operational characteristics, including locatingits disk image, quiesce the primary application for backup, instruct itto perform a backup, and/or un-quiesce it afterwards. If no such utilityis found, the enhanced data agent pushes a utility to the applicationfor these purposes. In contrast to a co-resident data agent, thisinstalled “application utility” occupies a minimal footprint on theprimary host. Fourth, the enhanced data agent also will determinewhether the application and/or its associated file system comprises anative utility (such as a log or journal or the like), for trackingchanged data blocks being generated and written by the application. Ifno such utility can be found, the enhanced data agent pushes anapplication-specific changed block filter to be installed on the primaryapplication's host. After a baseline full backup of theapplication-specific disk image, the rest of Live Sync relies on thechanged block filter (whether native or installed by the enhanced dataagent) to capture changed blocks for updating the standby copy of theapplication's disk image which is maintained at the standby/failovercomputing platform. Like the installed application utility, theinstalled changed block filter also has a minimal footprint. Fifth, theenhanced data agent is capable of supporting the Live Synchronization ofa number of distinct primary applications executing on one or morecomputing platforms—in contrast to the traditional one-on-one pairing ofa primary application with a co-resident data agent installed on theapplication's host.

In some embodiments, the changed data blocks from the primaryapplications are continuously replicated to the standby copy of the diskimage. Therefore, the synchronized application closely mirrors thechanges occurring at the primary application so that when it boots upfrom the standby disk image there is minimal, if any, loss of datarelative to the primary application.

In some alternative embodiments and/or in reference to other primaryapplications in the illustrative system, instead of continuous datareplication, the changed data blocks from the primary application arebacked up as incremental backups to an intermediary secondary storage,e.g., hourly. From there, the incremental backups are synchronized tothe standby copy of the disk image at the standby/failover destination.This latter step may occur immediately after the incremental backup ismade or may occur on a delayed schedule, e.g., daily. If a delayedschedule is used, the incremental backups are not immediately applied tothe standby disk image, and instead several incremental backups areallowed to accumulate before being applied. For example, incrementalbackups that occur hourly may be synchronized to the standby/failoverdestination daily. In such a scenario, the multiple incremental backupsare analyzed and only the most current changed data blocks aretransmitted from the intermediary secondary storage to thestandby/failover destination. In other words, rather than “replaying”each incremental backup in turn, only the minimum set of changed blocksis applied, thereby reducing churn. The incremental backups are retainedin secondary storage as point-in-time backups in case the primaryapplication or standby application needs to revert to a certain earlierpoint in time, e.g., a known good state. This might be required if atest of the synchronized application reveals a boot failure or someother data corruption. In such a case, when the synchronized applicationis activated for taking over from the primary application, it wouldbegin operating from a disk image from an earlier known good point intime rather than using the latest incremental backup.

The enhanced data agent comprises sub-components or functional modulesin some embodiments. For example, an illustrative enhanced data agentcomprises any number of application-specific connectors forcommunicating with the application hosts and with the discoveredapplications, whether communicating with the applications' respectivenative connector/API or with an installed application utility pushedthereto by the enhanced data agent. A given application-specificconnector in the enhanced data agent queries the application foroperational characteristics and identifies/locates the application'sdisk image, transmits quiesce commands to the application inanticipation of a backup operation, and correspondingly transmitsun-quiesce commands after the backup completes. Some applicationscomprise self-backup functionality and the exemplaryapplication-specific connector in the enhanced data agent can instructthe targeted application to perform a full backup which acts as abaseline for changed block tracking afterwards.

The enhanced data agent also comprises secondary copy controlfunctionality that transmits control messages to and receives changeddata blocks from the targeted application. For example, a secondary copycontroller detects whether the application or associated file systemcomprises a native tracker for changed data blocks; if not, thesecondary copy controller pushes a changed block filter thereto.Thereafter the secondary copy controller maintains communications withthe native or installed changed block filter to obtain the changedblocks and/or to route the changed blocks to an assigned media agent.

In the case of incremental backups that accumulate at an intermediarysecondary storage device, the secondary copy controller in the enhanceddata agent performs an analysis of the multiple accumulated incrementalbackups and generates a “unified” or “final” version that comprises onlythe latest changes as to any given data block relative to the precedingrestore to the standby computing platform. This unified or final versionof the accumulated changed data blocks is then transmitted to thestandby computing platform in the form of a restore operation thatupdates the standby copy of the application's disk image so that theapplication can be said to be synchronized. This approach advantageouslyreduces the bandwidth required in communicating with the destinationcomputing platform and is also speedier, as less data block churn occursat the standby/failover destination.

In addition to the enhancements described above, the illustrative systemfurther comprises an enhanced storage manager that transmits queries tothe enhanced data agent asking about applications in the illustrativesystem. In response to receiving such a query, the enhanced data agentbegins the process of automatic discovery of the applications and theiroperational properties, such as type of application, file systemconfiguration, primary data configuration (e.g., storage volume IDs) anddisk image (e.g., VMDK). The enhanced storage manager may instruct theenhanced data agent to proceed with further discovery of whetherconnectors/APIs and/or changed block trackers are natively available inthe discovered applications. In some alternative embodiments, theenhanced data agent performs these discovery steps autonomously withoutexplicit instruction from the storage manager. The storage manager mayfurther provide scheduling information to the enhanced data agent, e.g.,how often to execute incremental backups and how often to synchronizethe backups to the standby destination.

On receiving the discovery information about the applications from theenhanced data agent, the storage manager may analyze the nature of thediscovered applications and may apply certain priorities or rules. Forexample, certain applications, e.g., Oracle DBMS, may be treated withhighest priority for Live Synchronization, whereas other applications,e.g., Microsoft Office applications (E.g., Word, Excel, etc.) will bebacked up but not Live Synched. Accordingly, the storage manager maythen instruct the enhanced data on which applications are to be LiveSynched and where their standby destinations are to be configured. Thestorage manager is still responsible for managing the illustrativestorage management system as a whole, e.g., controlling storageoperations and other information management operations, maintaining amanagement database, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary informationmanagement system.

FIG. 1B is a detailed view of a primary storage device, a secondarystorage device, and some examples of primary data and secondary copydata.

FIG. 1C is a block diagram of an exemplary information management systemincluding a storage manager, one or more data agents, and one or moremedia agents.

FIG. 1D is a block diagram illustrating a scalable informationmanagement system.

FIG. 1E illustrates certain secondary copy operations according to anexemplary storage policy.

FIGS. 1F-1H are block diagrams illustrating suitable data structuresthat may be employed by the information management system.

FIG. 2 is a block diagram illustrating some salient portions of a system200 for application-level Live Synchronization across computingplatforms, according to an illustrative embodiment of the presentinvention that uses incremental backups and delayed synchronization.

FIG. 3 is a block diagram illustrating some salient portions of a system300 for application-level Live Synchronization using block-levelcontinuous data replication, according to another illustrativeembodiment of the present invention.

FIG. 4A is a block diagram illustrating some details of system 300,including logical pathways between certain components for LiveSynchronization of an illustrative application 110-1 using block-levelcontinuous data replication from primary disk image to a standby copy innative application format.

FIG. 4B is a block diagram illustrating some details of system 300,including logical pathways between certain components for LiveSynchronization of an illustrative application 110-1 using block-levelcontinuous data replication from primary disk image to a standby copyand further depicting creating application-consistent (point-in-time)recovery points via snapshots taken at the standby/failover destination.

FIG. 4C is a block diagram illustrating some details of system 300,including the use of a media agent to save application-consistent(point-in-time) recovery points to secondary storage when usingblock-level continuous data replication to Live Synchronize anapplication 110-1.

FIG. 5 is a block diagram illustrating some details of system 300,including logical pathways between certain components for LiveSynchronization of an illustrative application 110-2 using block-levelcontinuous data replication to the standby copy of the disk image.

FIG. 6 is a block diagram illustrating some details of system 200 or300, including logical pathways between certain components for LiveSynchronization of an illustrative application 110-n using block-levelcontinuous data replication to the standby copy of the disk image.

FIG. 7 depicts some salient operations of a method 700 according to anillustrative embodiment of the present invention.

FIG. 8A depicts some salient sub-operations of block 704 in method 700.

FIG. 8B depicts some salient sub-operations of block 712 in method 700.

FIG. 9A depicts some salient sub-operations of block 714 in method 700.

FIG. 9B depicts some salient sub-operations of block 716 in method 700.

FIG. 10 is a block diagram illustrating some salient portions of ahybrid system 200/300 for application-level Live Sync depicting LiveSynchronization of co-resident applications to disparate standbydestinations and further depicting selectively synchronizing someapplications and not others among the co-resident applications.

DETAILED DESCRIPTION

Descriptions and examples of systems and methods according to one ormore illustrative embodiments of the present invention may be found inthe section entitled APPLICATION-LEVEL LIVE SYNCHRONIZATION ACROSSCOMPUTING PLATFORMS INCLUDING SYNCHRONIZING CO-RESIDENT APPLICATIONS TODISPARATE STANDBY DESTINATIONS AND SELECTIVELY SYNCHRONIZING SOMEAPPLICATIONS AND NOT OTHERS, as well as in the section entitled ExampleEmbodiments, and also in FIGS. 2-10 herein. Furthermore, components andfunctionality for application-level Live Synchronization may beconfigured and/or incorporated into information management systems suchas those described herein in FIGS. 1A-1H.

Various embodiments described herein are intimately tied to, enabled by,and would not exist except for, computer technology. For example,application-level Live Synchronization, including auto-discoveringapplications in a storage management system, communications betweenenhanced data agents and targeted applications, as well asapplication-level data block backups and replication as described hereinin reference to various embodiments cannot reasonably be performed byhumans alone, without the computer technology upon which they areimplemented.

Information Management System Overview

With the increasing importance of protecting and leveraging data,organizations simply cannot risk losing critical data. Moreover, runawaydata growth and other modern realities make protecting and managing dataincreasingly difficult. There is therefore a need for efficient,powerful, and user-friendly solutions for protecting and managing dataand for smart and efficient management of data storage. Depending on thesize of the organization, there may be many data production sourceswhich are under the purview of tens, hundreds, or even thousands ofindividuals. In the past, individuals were sometimes responsible formanaging and protecting their own data, and a patchwork of hardware andsoftware point solutions may have been used in any given organization.These solutions were often provided by different vendors and had limitedor no interoperability. Certain embodiments described herein addressthese and other shortcomings of prior approaches by implementingscalable, unified, organization-wide information management, includingdata storage management.

FIG. 1A shows one such information management system 100 (or “system100”), which generally includes combinations of hardware and softwareconfigured to protect and manage data and metadata that are generatedand used by computing devices in system 100. System 100 may be referredto in some embodiments as a “storage management system” or a “datastorage management system.” System 100 performs information managementoperations, some of which may be referred to as “storage operations” or“data storage operations,” to protect and manage the data residing inand/or managed by system 100. The organization that employs system 100may be a corporation or other business entity, non-profit organization,educational institution, household, governmental agency, or the like.

Generally, the systems and associated components described herein may becompatible with and/or provide some or all of the functionality of thesystems and corresponding components described in one or more of thefollowing U.S. patents/publications and patent applications assigned toCommvault Systems, Inc., each of which is hereby incorporated byreference in its entirety herein:

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System 100 includes computing devices and computing technologies. Forinstance, system 100 can include one or more client computing devices102 and secondary storage computing devices 106, as well as storagemanager 140 or a host computing device for it. Computing devices caninclude, without limitation, one or more: workstations, personalcomputers, desktop computers, or other types of generally fixedcomputing systems such as mainframe computers, servers, andminicomputers. Other computing devices can include mobile or portablecomputing devices, such as one or more laptops, tablet computers,personal data assistants, mobile phones (such as smartphones), and othermobile or portable computing devices such as embedded computers, set topboxes, vehicle-mounted devices, wearable computers, etc. Servers caninclude mail servers, file servers, database servers, virtual machineservers, and web servers. Any given computing device comprises one ormore processors (e.g., CPU and/or single-core or multi-core processors),as well as corresponding non-transitory computer memory (e.g.,random-access memory (RAM)) for storing computer programs which are tobe executed by the one or more processors. Other computer memory formass storage of data may be packaged/configured with the computingdevice (e.g., an internal hard disk) and/or may be external andaccessible by the computing device (e.g., network-attached storage, astorage array, etc.). In some cases, a computing device includes cloudcomputing resources, which may be implemented as virtual machines. Forinstance, one or more virtual machines may be provided to theorganization by a third-party cloud service vendor.

In some embodiments, computing devices can include one or more virtualmachine(s) running on a physical host computing device (or “hostmachine”) operated by the organization. As one example, the organizationmay use one virtual machine as a database server and another virtualmachine as a mail server, both virtual machines operating on the samehost machine. A Virtual machine (“VM”) is a software implementation of acomputer that does not physically exist and is instead instantiated inan operating system of a physical computer (or host machine) to enableapplications to execute within the VM's environment, i.e., a VM emulatesa physical computer. AVM includes an operating system and associatedvirtual resources, such as computer memory and processor(s). Ahypervisor operates between the VM and the hardware of the physical hostmachine and is generally responsible for creating and running the VMs.Hypervisors are also known in the art as virtual machine monitors or avirtual machine managers or “VMMs”, and may be implemented in software,firmware, and/or specialized hardware installed on the host machine.Examples of hypervisors include ESX Server, by VMware, Inc. of PaloAlto, Calif.; Microsoft Virtual Server and Microsoft Windows ServerHyper-V, both by Microsoft Corporation of Redmond, Wash.; Sun xVM byOracle America Inc. of Santa Clara, Calif.; and Xen by Citrix Systems,Santa Clara, Calif. The hypervisor provides resources to each virtualoperating system such as a virtual processor, virtual memory, a virtualnetwork device, and a virtual disk. Each virtual machine has one or moreassociated virtual disks. The hypervisor typically stores the data ofvirtual disks in files on the file system of the physical host machine,called virtual machine disk files (“VMDK” in VMware lingo) or virtualhard disk image files (in Microsoft lingo). For example, VMware's ESXServer provides the Virtual Machine File System (VMFS) for the storageof virtual machine disk files. A virtual machine reads data from andwrites data to its virtual disk much the way that a physical machinereads data from and writes data to a physical disk. Examples oftechniques for implementing information management in a cloud computingenvironment are described in U.S. Pat. No. 8,285,681. Examples oftechniques for implementing information management in a virtualizedcomputing environment are described in U.S. Pat. No. 8,307,177.

Information management system 100 can also include electronic datastorage devices, generally used for mass storage of data, including,e.g., primary storage devices 104 and secondary storage devices 108.Storage devices can generally be of any suitable type including, withoutlimitation, disk drives, storage arrays (e.g., storage-area network(SAN) and/or network-attached storage (NAS) technology), semiconductormemory (e.g., solid state storage devices), network attached storage(NAS) devices, tape libraries, or other magnetic, non-tape storagedevices, optical media storage devices, DNA/RNA-based memory technology,combinations of the same, etc. In some embodiments, storage devices formpart of a distributed file system. In some cases, storage devices areprovided in a cloud storage environment (e.g., a private cloud or oneoperated by a third-party vendor), whether for primary data or secondarycopies or both.

Depending on context, the term “information management system” can referto generally all of the illustrated hardware and software components inFIG. 1C, or the term may refer to only a subset of the illustratedcomponents. For instance, in some cases, system 100 generally refers toa combination of specialized components used to protect, move, manage,manipulate, analyze, and/or process data and metadata generated byclient computing devices 102. However, system 100 in some cases does notinclude the underlying components that generate and/or store primarydata 112, such as the client computing devices 102 themselves, and theprimary storage devices 104. Likewise secondary storage devices 108(e.g., a third-party provided cloud storage environment) may not be partof system 100. As an example, “information management system” or“storage management system” may sometimes refer to one or more of thefollowing components, which will be described in further detail below:storage manager, data agent, and media agent.

One or more client computing devices 102 may be part of system 100, eachclient computing device 102 having an operating system and at least oneapplication 110 and one or more accompanying data agents executingthereon; and associated with one or more primary storage devices 104storing primary data 112. Client computing device(s) 102 and primarystorage devices 104 may generally be referred to in some cases asprimary storage subsystem 117.

Client Computing Devices, Clients, and Subclients

Typically, a variety of sources in an organization produce data to beprotected and managed. As just one illustrative example, in a corporateenvironment such data sources can be employee workstations and companyservers such as a mail server, a web server, a database server, atransaction server, or the like. In system 100, data generation sourcesinclude one or more client computing devices 102. A computing devicethat has a data agent 142 installed and operating on it is generallyreferred to as a “client computing device” 102, and may include any typeof computing device, without limitation. A client computing device 102may be associated with one or more users and/or user accounts.

A “client” is a logical component of information management system 100,which may represent a logical grouping of one or more data agentsinstalled on a client computing device 102. Storage manager 140recognizes a client as a component of system 100, and in someembodiments, may automatically create a client component the first timea data agent 142 is installed on a client computing device 102. Becausedata generated by executable component(s) 110 is tracked by theassociated data agent 142 so that it may be properly protected in system100, a client may be said to generate data and to store the generateddata to primary storage, such as primary storage device 104. However,the terms “client” and “client computing device” as used herein do notimply that a client computing device 102 is necessarily configured inthe client/server sense relative to another computing device such as amail server, or that a client computing device 102 cannot be a server inits own right. As just a few examples, a client computing device 102 canbe and/or include mail servers, file servers, database servers, virtualmachine servers, and/or web servers.

Each client computing device 102 may have application(s) 110 executingthereon which generate and manipulate the data that is to be protectedfrom loss and managed in system 100. Applications 110 generallyfacilitate the operations of an organization, and can include, withoutlimitation, mail server applications (e.g., Microsoft Exchange Server),file system applications, mail client applications (e.g., MicrosoftExchange Client), database applications or database management systems(e.g., SQL, Oracle, SAP, Lotus Notes Database), word processingapplications (e.g., Microsoft Word), spreadsheet applications, financialapplications, presentation applications, graphics and/or videoapplications, browser applications, mobile applications, entertainmentapplications, and so on. Each application 110 may be accompanied by anapplication-specific data agent 142, though not all data agents 142 areapplication-specific or associated with only application. A file system,e.g., Microsoft Windows Explorer, may be considered an application 110and may be accompanied by its own data agent 142. Client computingdevices 102 can have at least one operating system (e.g., MicrosoftWindows, Mac OS X, iOS, IBM z/OS, Linux, other Unix-based operatingsystems, etc.) installed thereon, which may support or host one or morefile systems and other applications 110. In some embodiments, a virtualmachine that executes on a host client computing device 102 may beconsidered an application 110 and may be accompanied by a specific dataagent 142 (e.g., virtual server data agent).

Client computing devices 102 and other components in system 100 can beconnected to one another via one or more electronic communicationpathways 114. For example, a first communication pathway 114 maycommunicatively couple client computing device 102 and secondary storagecomputing device 106; a second communication pathway 114 maycommunicatively couple storage manager 140 and client computing device102; and a third communication pathway 114 may communicatively couplestorage manager 140 and secondary storage computing device 106, etc.(see, e.g., FIG. 1A and FIG. 1C). A communication pathway 114 caninclude one or more networks or other connection types including one ormore of the following, without limitation: the Internet, a wide areanetwork (WAN), a local area network (LAN), a Storage Area Network (SAN),a Fibre Channel (FC) connection, a Small Computer System Interface(SCSI) connection, a virtual private network (VPN), a token ring orTCP/IP based network, an intranet network, a point-to-point link, acellular network, a wireless data transmission system, a two-way cablesystem, an interactive kiosk network, a satellite network, a broadbandnetwork, a baseband network, a neural network, a mesh network, an ad hocnetwork, other appropriate computer or telecommunications networks,combinations of the same or the like. Communication pathways 114 in somecases may also include application programming interfaces (APIs)including, e.g., cloud service provider APIs, virtual machine managementAPIs, and hosted service provider APIs. The underlying infrastructure ofcommunication pathways 114 may be wired and/or wireless, analog and/ordigital, or any combination thereof; and the facilities used may beprivate, public, third-party provided, or any combination thereof,without limitation.

A “subclient” is a logical grouping of all or part of a client's primarydata 112. In general, a subclient may be defined according to how thesubclient data is to be protected as a unit in system 100. For example,a subclient may be associated with a certain storage policy. A givenclient may thus comprise several subclients, each subclient associatedwith a different storage policy. For example, some files may form afirst subclient that requires compression and deduplication and isassociated with a first storage policy. Other files of the client mayform a second subclient that requires a different retention schedule aswell as encryption, and may be associated with a different, secondstorage policy. As a result, though the primary data may be generated bythe same application 110 and may belong to one given client, portions ofthe data may be assigned to different subclients for distinct treatmentby system 100. More detail on subclients is given in regard to storagepolicies below.

Primary Data and Exemplary Primary Storage Devices

Primary data 112 is generally production data or “live” data generatedby the operating system and/or applications 110 executing on clientcomputing device 102. Primary data 112 is generally stored on primarystorage device(s) 104 and is organized via a file system operating onthe client computing device 102. Thus, client computing device(s) 102and corresponding applications 110 may create, access, modify, write,delete, and otherwise use primary data 112. Primary data 112 isgenerally in the native format of the source application 110. Primarydata 112 is an initial or first stored body of data generated by thesource application 110. Primary data 112 in some cases is createdsubstantially directly from data generated by the corresponding sourceapplication 110. It can be useful in performing certain tasks toorganize primary data 112 into units of different granularities. Ingeneral, primary data 112 can include files, directories, file systemvolumes, data blocks, extents, or any other hierarchies or organizationsof data objects. As used herein, a “data object” can refer to (i) anyfile that is currently addressable by a file system or that waspreviously addressable by the file system (e.g., an archive file),and/or to (ii) a subset of such a file (e.g., a data block, an extent,etc.). Primary data 112 may include structured data (e.g., databasefiles), unstructured data (e.g., documents), and/or semi-structureddata. See, e.g., FIG. 1B.

It can also be useful in performing certain functions of system 100 toaccess and modify metadata within primary data 112. Metadata generallyincludes information about data objects and/or characteristicsassociated with the data objects. For simplicity herein, it is to beunderstood that, unless expressly stated otherwise, any reference toprimary data 112 generally also includes its associated metadata, butreferences to metadata generally do not include the primary data.Metadata can include, without limitation, one or more of the following:the data owner (e.g., the client or user that generates the data), thelast modified time (e.g., the time of the most recent modification ofthe data object), a data object name (e.g., a file name), a data objectsize (e.g., a number of bytes of data), information about the content(e.g., an indication as to the existence of a particular search term),user-supplied tags, to/from information for email (e.g., an emailsender, recipient, etc.), creation date, file type (e.g., format orapplication type), last accessed time, application type (e.g., type ofapplication that generated the data object), location/network (e.g., acurrent, past or future location of the data object and network pathwaysto/from the data object), geographic location (e.g., GPS coordinates),frequency of change (e.g., a period in which the data object ismodified), business unit (e.g., a group or department that generates,manages or is otherwise associated with the data object), aginginformation (e.g., a schedule, such as a time period, in which the dataobject is migrated to secondary or long term storage), boot sectors,partition layouts, file location within a file folder directorystructure, user permissions, owners, groups, access control lists(ACLs), system metadata (e.g., registry information), combinations ofthe same or other similar information related to the data object. Inaddition to metadata generated by or related to file systems andoperating systems, some applications 110 and/or other components ofsystem 100 maintain indices of metadata for data objects, e.g., metadataassociated with individual email messages. The use of metadata toperform classification and other functions is described in greaterdetail below.

Primary storage devices 104 storing primary data 112 may be relativelyfast and/or expensive technology (e.g., flash storage, a disk drive, ahard-disk storage array, solid state memory, etc.), typically to supporthigh-performance live production environments. Primary data 112 may behighly changeable and/or may be intended for relatively short termretention (e.g., hours, days, or weeks). According to some embodiments,client computing device 102 can access primary data 112 stored inprimary storage device 104 by making conventional file system calls viathe operating system. Each client computing device 102 is generallyassociated with and/or in communication with one or more primary storagedevices 104 storing corresponding primary data 112. A client computingdevice 102 is said to be associated with or in communication with aparticular primary storage device 104 if it is capable of one or moreof: routing and/or storing data (e.g., primary data 112) to the primarystorage device 104, coordinating the routing and/or storing of data tothe primary storage device 104, retrieving data from the primary storagedevice 104, coordinating the retrieval of data from the primary storagedevice 104, and modifying and/or deleting data in the primary storagedevice 104. Thus, a client computing device 102 may be said to accessdata stored in an associated storage device 104.

Primary storage device 104 may be dedicated or shared. In some cases,each primary storage device 104 is dedicated to an associated clientcomputing device 102, e.g., a local disk drive. In other cases, one ormore primary storage devices 104 can be shared by multiple clientcomputing devices 102, e.g., via a local network, in a cloud storageimplementation, etc. As one example, primary storage device 104 can be astorage array shared by a group of client computing devices 102, such asEMC Clariion, EMC Symmetrix, EMC Celerra, Dell EqualLogic, IBM XIV,NetApp FAS, HP EVA, and HP 3PAR.

System 100 may also include hosted services (not shown), which may behosted in some cases by an entity other than the organization thatemploys the other components of system 100. For instance, the hostedservices may be provided by online service providers. Such serviceproviders can provide social networking services, hosted email services,or hosted productivity applications or other hosted applications such assoftware-as-a-service (SaaS), platform-as-a-service (PaaS), applicationservice providers (ASPs), cloud services, or other mechanisms fordelivering functionality via a network. As it services users, eachhosted service may generate additional data and metadata, which may bemanaged by system 100, e.g., as primary data 112. In some cases, thehosted services may be accessed using one of the applications 110. As anexample, a hosted mail service may be accessed via browser running on aclient computing device 102.

Secondary Copies and Exemplary Secondary Storage Devices

Primary data 112 stored on primary storage devices 104 may becompromised in some cases, such as when an employee deliberately oraccidentally deletes or overwrites primary data 112. Or primary storagedevices 104 can be damaged, lost, or otherwise corrupted. For recoveryand/or regulatory compliance purposes, it is therefore useful togenerate and maintain copies of primary data 112. Accordingly, system100 includes one or more secondary storage computing devices 106 and oneor more secondary storage devices 108 configured to create and store oneor more secondary copies 116 of primary data 112 including itsassociated metadata. The secondary storage computing devices 106 and thesecondary storage devices 108 may be referred to as secondary storagesubsystem 118.

Secondary copies 116 can help in search and analysis efforts and meetother information management goals as well, such as: restoring dataand/or metadata if an original version is lost (e.g., by deletion,corruption, or disaster); allowing point-in-time recovery; complyingwith regulatory data retention and electronic discovery (e-discovery)requirements; reducing utilized storage capacity in the productionsystem and/or in secondary storage; facilitating organization and searchof data; improving user access to data files across multiple computingdevices and/or hosted services; and implementing data retention andpruning policies.

A secondary copy 116 can comprise a separate stored copy of data that isderived from one or more earlier-created stored copies (e.g., derivedfrom primary data 112 or from another secondary copy 116). Secondarycopies 116 can include point-in-time data, and may be intended forrelatively long-term retention before some or all of the data is movedto other storage or discarded. In some cases, a secondary copy 116 maybe in a different storage device than other previously stored copies;and/or may be remote from other previously stored copies. Secondarycopies 116 can be stored in the same storage device as primary data 112.For example, a disk array capable of performing hardware snapshotsstores primary data 112 and creates and stores hardware snapshots of theprimary data 112 as secondary copies 116. Secondary copies 116 may bestored in relatively slow and/or lower cost storage (e.g., magnetictape). A secondary copy 116 may be stored in a backup or archive format,or in some other format different from the native source applicationformat or other format of primary data 112.

Secondary storage computing devices 106 may index secondary copies 116(e.g., using a media agent 144), enabling users to browse and restore ata later time and further enabling the lifecycle management of theindexed data. After creation of a secondary copy 116 that representscertain primary data 112, a pointer or other location indicia (e.g., astub) may be placed in primary data 112, or be otherwise associated withprimary data 112, to indicate the current location of a particularsecondary copy 116. Since an instance of a data object or metadata inprimary data 112 may change over time as it is modified by application110 (or hosted service or the operating system), system 100 may createand manage multiple secondary copies 116 of a particular data object ormetadata, each copy representing the state of the data object in primarydata 112 at a particular point in time. Moreover, since an instance of adata object in primary data 112 may eventually be deleted from primarystorage device 104 and the file system, system 100 may continue tomanage point-in-time representations of that data object, even thoughthe instance in primary data 112 no longer exists. For virtual machines,the operating system and other applications 110 of client computingdevice(s) 102 may execute within or under the management ofvirtualization software (e.g., a VMM), and the primary storage device(s)104 may comprise a virtual disk created on a physical storage device.System 100 may create secondary copies 116 of the files or other dataobjects in a virtual disk file and/or secondary copies 116 of the entirevirtual disk file itself (e.g., of an entire .vmdk file).

Secondary copies 116 are distinguishable from corresponding primary data112. First, secondary copies 116 can be stored in a different formatfrom primary data 112 (e.g., backup, archive, or other non-nativeformat). For this or other reasons, secondary copies 116 may not bedirectly usable by applications 110 or client computing device 102(e.g., via standard system calls or otherwise) without modification,processing, or other intervention by system 100 which may be referred toas “restore” operations. Secondary copies 116 may have been processed bydata agent 142 and/or media agent 144 in the course of being created(e.g., compression, deduplication, encryption, integrity markers,indexing, formatting, application-aware metadata, etc.), and thussecondary copy 116 may represent source primary data 112 withoutnecessarily being exactly identical to the source.

Second, secondary copies 116 may be stored on a secondary storage device108 that is inaccessible to application 110 running on client computingdevice 102 and/or hosted service. Some secondary copies 116 may be“offline copies,” in that they are not readily available (e.g., notmounted to tape or disk). Offline copies can include copies of data thatsystem 100 can access without human intervention (e.g., tapes within anautomated tape library, but not yet mounted in a drive), and copies thatthe system 100 can access only with some human intervention (e.g., tapeslocated at an offsite storage site).

Using Intermediate Devices for Creating Secondary Copies—SecondaryStorage Computing Devices

Creating secondary copies can be challenging when hundreds or thousandsof client computing devices 102 continually generate large volumes ofprimary data 112 to be protected. Also, there can be significantoverhead involved in the creation of secondary copies 116. Moreover,specialized programmed intelligence and/or hardware capability isgenerally needed for accessing and interacting with secondary storagedevices 108. Client computing devices 102 may interact directly with asecondary storage device 108 to create secondary copies 116, but in viewof the factors described above, this approach can negatively impact theability of client computing device 102 to serve/service application 110and produce primary data 112. Further, any given client computing device102 may not be optimized for interaction with certain secondary storagedevices 108.

Thus, system 100 may include one or more software and/or hardwarecomponents which generally act as intermediaries between clientcomputing devices 102 (that generate primary data 112) and secondarystorage devices 108 (that store secondary copies 116). In addition tooff-loading certain responsibilities from client computing devices 102,these intermediate components provide other benefits. For instance, asdiscussed further below with respect to FIG. 1D, distributing some ofthe work involved in creating secondary copies 116 can enhancescalability and improve system performance. For instance, usingspecialized secondary storage computing devices 106 and media agents 144for interfacing with secondary storage devices 108 and/or for performingcertain data processing operations can greatly improve the speed withwhich system 100 performs information management operations and can alsoimprove the capacity of the system to handle large numbers of suchoperations, while reducing the computational load on the productionenvironment of client computing devices 102. The intermediate componentscan include one or more secondary storage computing devices 106 as shownin FIG. 1A and/or one or more media agents 144. Media agents arediscussed further below (e.g., with respect to FIGS. 1C-1E). Thesespecial-purpose components of system 100 comprise specialized programmedintelligence and/or hardware capability for writing to, reading from,instructing, communicating with, or otherwise interacting with secondarystorage devices 108.

Secondary storage computing device(s) 106 can comprise any of thecomputing devices described above, without limitation. In some cases,secondary storage computing device(s) 106 also include specializedhardware componentry and/or software intelligence (e.g., specializedinterfaces) for interacting with certain secondary storage device(s) 108with which they may be specially associated.

To create a secondary copy 116 involving the copying of data fromprimary storage subsystem 117 to secondary storage subsystem 118, clientcomputing device 102 may communicate the primary data 112 to be copied(or a processed version thereof generated by a data agent 142) to thedesignated secondary storage computing device 106, via a communicationpathway 114. Secondary storage computing device 106 in turn may furtherprocess and convey the data or a processed version thereof to secondarystorage device 108. One or more secondary copies 116 may be created fromexisting secondary copies 116, such as in the case of an auxiliary copyoperation, described further below.

Exemplary Primary Data and an Exemplary Secondary Copy

FIG. 1B is a detailed view of some specific examples of primary datastored on primary storage device(s) 104 and secondary copy data storedon secondary storage device(s) 108, with other components of the systemremoved for the purposes of illustration. Stored on primary storagedevice(s) 104 are primary data 112 objects including word processingdocuments 119A-B, spreadsheets 120, presentation documents 122, videofiles 124, image files 126, email mailboxes 128 (and corresponding emailmessages 129A-C), HTML/XML or other types of markup language files 130,databases 132 and corresponding tables or other data structures133A-133C. Some or all primary data 112 objects are associated withcorresponding metadata (e.g., “Meta1-11”), which may include file systemmetadata and/or application-specific metadata. Stored on the secondarystorage device(s) 108 are secondary copy 116 data objects 134A-C whichmay include copies of or may otherwise represent corresponding primarydata 112.

Secondary copy data objects 134A-C can individually represent more thanone primary data object. For example, secondary copy data object 134Arepresents three separate primary data objects 133C, 122, and 129C(represented as 133C′, 122′, and 129C′, respectively, and accompanied bycorresponding metadata Meta11, Meta3, and Meta8, respectively).Moreover, as indicated by the prime mark (′), secondary storagecomputing devices 106 or other components in secondary storage subsystem118 may process the data received from primary storage subsystem 117 andstore a secondary copy including a transformed and/or supplementedrepresentation of a primary data object and/or metadata that isdifferent from the original format, e.g., in a compressed, encrypted,deduplicated, or other modified format. For instance, secondary storagecomputing devices 106 can generate new metadata or other informationbased on said processing, and store the newly generated informationalong with the secondary copies. Secondary copy data object 134Brepresents primary data objects 120, 133B, and 119A as 120′, 133B′, and119A′, respectively, accompanied by corresponding metadata Meta2,Meta10, and Meta1, respectively. Also, secondary copy data object 134Crepresents primary data objects 133A, 119B, and 129A as 133A′, 119B′,and 129A′, respectively, accompanied by corresponding metadata Meta9,Meta5, and Meta6, respectively.

Exemplary Information Management System Architecture

System 100 can incorporate a variety of different hardware and softwarecomponents, which can in turn be organized with respect to one anotherin many different configurations, depending on the embodiment. There arecritical design choices involved in specifying the functionalresponsibilities of the components and the role of each component insystem 100. Such design choices can impact how system 100 performs andadapts to data growth and other changing circumstances. FIG. 1C shows asystem 100 designed according to these considerations and includes:storage manager 140, one or more data agents 142 executing on clientcomputing device(s) 102 and configured to process primary data 112, andone or more media agents 144 executing on one or more secondary storagecomputing devices 106 for performing tasks involving secondary storagedevices 108.

Storage Manager

Storage manager 140 is a centralized storage and/or information managerthat is configured to perform certain control functions and also tostore certain critical information about system 100—hence storagemanager 140 is said to manage system 100. As noted, the number ofcomponents in system 100 and the amount of data under management can belarge. Managing the components and data is therefore a significant task,which can grow unpredictably as the number of components and data scaleto meet the needs of the organization. For these and other reasons,according to certain embodiments, responsibility for controlling system100, or at least a significant portion of that responsibility, isallocated to storage manager 140. Storage manager 140 can be adaptedindependently according to changing circumstances, without having toreplace or re-design the remainder of the system. Moreover, a computingdevice for hosting and/or operating as storage manager 140 can beselected to best suit the functions and networking needs of storagemanager 140. These and other advantages are described in further detailbelow and with respect to FIG. 1D.

Storage manager 140 may be a software module or other application hostedby a suitable computing device. In some embodiments, storage manager 140is itself a computing device that performs the functions describedherein. Storage manager 140 comprises or operates in conjunction withone or more associated data structures such as a dedicated database(e.g., management database 146), depending on the configuration. Thestorage manager 140 generally initiates, performs, coordinates, and/orcontrols storage and other information management operations performedby system 100, e.g., to protect and control primary data 112 andsecondary copies 116. In general, storage manager 140 is said to managesystem 100, which includes communicating with, instructing, andcontrolling in some circumstances components such as data agents 142 andmedia agents 144, etc.

As shown by the dashed arrowed lines 114 in FIG. 1C, storage manager 140may communicate with, instruct, and/or control some or all elements ofsystem 100, such as data agents 142 and media agents 144. In thismanner, storage manager 140 manages the operation of various hardwareand software components in system 100. In certain embodiments, controlinformation originates from storage manager 140 and status as well asindex reporting is transmitted to storage manager 140 by the managedcomponents, whereas payload data and metadata are generally communicatedbetween data agents 142 and media agents 144 (or otherwise betweenclient computing device(s) 102 and secondary storage computing device(s)106), e.g., at the direction of and under the management of storagemanager 140. Control information can generally include parameters andinstructions for carrying out information management operations, suchas, without limitation, instructions to perform a task associated withan operation, timing information specifying when to initiate a task,data path information specifying what components to communicate with oraccess in carrying out an operation, and the like. In other embodiments,some information management operations are controlled or initiated byother components of system 100 (e.g., by media agents 144 or data agents142), instead of or in combination with storage manager 140.

According to certain embodiments, storage manager 140 provides one ormore of the following functions:

-   -   communicating with data agents 142 and media agents 144,        including transmitting instructions, messages, and/or queries,        as well as receiving status reports, index information,        messages, and/or queries, and responding to same;    -   initiating execution of information management operations;    -   initiating restore and recovery operations;    -   managing secondary storage devices 108 and inventory/capacity of        the same;    -   allocating secondary storage devices 108 for secondary copy        operations;    -   reporting, searching, and/or classification of data in system        100;    -   monitoring completion of and status reporting related to        information management operations and jobs;    -   tracking movement of data within system 100;    -   tracking age information relating to secondary copies 116,        secondary storage devices 108, comparing the age information        against retention guidelines, and initiating data pruning when        appropriate;    -   tracking logical associations between components in system 100;    -   protecting metadata associated with system 100, e.g., in        management database 146;    -   implementing job management, schedule management, event        management, alert management, reporting, job history        maintenance, user security management, disaster recovery        management, and/or user interfacing for system administrators        and/or end users of system 100;    -   sending, searching, and/or viewing of log files; and    -   implementing operations management functionality.

Storage manager 140 may maintain an associated database 146 (or “storagemanager database 146” or “management database 146”) ofmanagement-related data and information management policies 148.Database 146 is stored in computer memory accessible by storage manager140. Database 146 may include a management index 150 (or “index 150”) orother data structure(s) that may store: logical associations betweencomponents of the system; user preferences and/or profiles (e.g.,preferences regarding encryption, compression, or deduplication ofprimary data or secondary copies; preferences regarding the scheduling,type, or other aspects of secondary copy or other operations; mappingsof particular information management users or user accounts to certaincomputing devices or other components, etc.; management tasks; mediacontainerization; other useful data; and/or any combination thereof. Forexample, storage manager 140 may use index 150 to track logicalassociations between media agents 144 and secondary storage devices 108and/or movement of data to/from secondary storage devices 108. Forinstance, index 150 may store data associating a client computing device102 with a particular media agent 144 and/or secondary storage device108, as specified in an information management policy 148.

Administrators and others may configure and initiate certain informationmanagement operations on an individual basis. But while this may beacceptable for some recovery operations or other infrequent tasks, it isoften not workable for implementing on-going organization-wide dataprotection and management. Thus, system 100 may utilize informationmanagement policies 148 for specifying and executing informationmanagement operations on an automated basis. Generally, an informationmanagement policy 148 can include a stored data structure or otherinformation source that specifies parameters (e.g., criteria and rules)associated with storage management or other information managementoperations. Storage manager 140 can process an information managementpolicy 148 and/or index 150 and, based on the results, identify aninformation management operation to perform, identify the appropriatecomponents in system 100 to be involved in the operation (e.g., clientcomputing devices 102 and corresponding data agents 142, secondarystorage computing devices 106 and corresponding media agents 144, etc.),establish connections to those components and/or between thosecomponents, and/or instruct and control those components to carry outthe operation. In this manner, system 100 can translate storedinformation into coordinated activity among the various computingdevices in system 100.

Management database 146 may maintain information management policies 148and associated data, although information management policies 148 can bestored in computer memory at any appropriate location outside managementdatabase 146. For instance, an information management policy 148 such asa storage policy may be stored as metadata in a media agent database 152or in a secondary storage device 108 (e.g., as an archive copy) for usein restore or other information management operations, depending on theembodiment. Information management policies 148 are described furtherbelow. According to certain embodiments, management database 146comprises a relational database (e.g., an SQL database) for trackingmetadata, such as metadata associated with secondary copy operations(e.g., what client computing devices 102 and corresponding subclientdata were protected and where the secondary copies are stored and whichmedia agent 144 performed the storage operation(s)). This and othermetadata may additionally be stored in other locations, such as atsecondary storage computing device 106 or on the secondary storagedevice 108, allowing data recovery without the use of storage manager140 in some cases. Thus, management database 146 may comprise dataneeded to kick off secondary copy operations (e.g., storage policies,schedule policies, etc.), status and reporting information aboutcompleted jobs (e.g., status and error reports on yesterday's backupjobs), and additional information sufficient to enable restore anddisaster recovery operations (e.g., media agent associations, locationindexing, content indexing, etc.).

Storage manager 140 may include a jobs agent 156, a user interface 158,and a management agent 154, all of which may be implemented asinterconnected software modules or application programs. These aredescribed further below.

Jobs agent 156 in some embodiments initiates, controls, and/or monitorsthe status of some or all information management operations previouslyperformed, currently being performed, or scheduled to be performed bysystem 100. A job is a logical grouping of information managementoperations such as daily storage operations scheduled for a certain setof subclients (e.g., generating incremental block-level backup copies116 at a certain time every day for database files in a certaingeographical location). Thus, jobs agent 156 may access informationmanagement policies 148 (e.g., in management database 146) to determinewhen, where, and how to initiate/control jobs in system 100.

Storage Manager User Interfaces

User interface 158 may include information processing and displaysoftware, such as a graphical user interface (GUI), an applicationprogram interface (API), and/or other interactive interface(s) throughwhich users and system processes can retrieve information about thestatus of information management operations or issue instructions tostorage manager 140 and other components. Via user interface 158, usersmay issue instructions to the components in system 100 regardingperformance of secondary copy and recovery operations. For example, auser may modify a schedule concerning the number of pending secondarycopy operations. As another example, a user may employ the GUI to viewthe status of pending secondary copy jobs or to monitor the status ofcertain components in system 100 (e.g., the amount of capacity left in astorage device). Storage manager 140 may track information that permitsit to select, designate, or otherwise identify content indices,deduplication databases, or similar databases or resources or data setswithin its information management cell (or another cell) to be searchedin response to certain queries. Such queries may be entered by the userby interacting with user interface 158.

Various embodiments of information management system 100 may beconfigured and/or designed to generate user interface data usable forrendering the various interactive user interfaces described. The userinterface data may be used by system 100 and/or by another system,device, and/or software program (for example, a browser program), torender the interactive user interfaces. The interactive user interfacesmay be displayed on, for example, electronic displays (including, forexample, touch-enabled displays), consoles, etc., whetherdirect-connected to storage manager 140 or communicatively coupledremotely, e.g., via an internet connection. The present disclosuredescribes various embodiments of interactive and dynamic userinterfaces, some of which may be generated by user interface agent 158,and which are the result of significant technological development. Theuser interfaces described herein may provide improved human-computerinteractions, allowing for significant cognitive and ergonomicefficiencies and advantages over previous systems, including reducedmental workloads, improved decision-making, and the like. User interface158 may operate in a single integrated view or console (not shown). Theconsole may support a reporting capability for generating a variety ofreports, which may be tailored to a particular aspect of informationmanagement.

User interfaces are not exclusive to storage manager 140 and in someembodiments a user may access information locally from a computingdevice component of system 100. For example, some information pertainingto installed data agents 142 and associated data streams may beavailable from client computing device 102. Likewise, some informationpertaining to media agents 144 and associated data streams may beavailable from secondary storage computing device 106.

Storage Manager Management Agent

Management agent 154 can provide storage manager 140 with the ability tocommunicate with other components within system 100 and/or with otherinformation management cells via network protocols and applicationprogramming interfaces (APIs) including, e.g., HTTP, HTTPS, FTP, REST,virtualization software APIs, cloud service provider APIs, and hostedservice provider APIs, without limitation. Management agent 154 alsoallows multiple information management cells to communicate with oneanother. For example, system 100 in some cases may be one informationmanagement cell in a network of multiple cells adjacent to one anotheror otherwise logically related, e.g., in a WAN or LAN. With thisarrangement, the cells may communicate with one another throughrespective management agents 154. Inter-cell communications andhierarchy is described in greater detail in e.g., U.S. Pat. No.7,343,453.

Information Management Cell

An “information management cell” (or “storage operation cell” or “cell”)may generally include a logical and/or physical grouping of acombination of hardware and software components associated withperforming information management operations on electronic data,typically one storage manager 140 and at least one data agent 142(executing on a client computing device 102) and at least one mediaagent 144 (executing on a secondary storage computing device 106). Forinstance, the components shown in FIG. 1C may together form aninformation management cell. Thus, in some configurations, a system 100may be referred to as an information management cell or a storageoperation cell. A given cell may be identified by the identity of itsstorage manager 140, which is generally responsible for managing thecell.

Multiple cells may be organized hierarchically, so that cells mayinherit properties from hierarchically superior cells or be controlledby other cells in the hierarchy (automatically or otherwise).Alternatively, in some embodiments, cells may inherit or otherwise beassociated with information management policies, preferences,information management operational parameters, or other properties orcharacteristics according to their relative position in a hierarchy ofcells. Cells may also be organized hierarchically according to function,geography, architectural considerations, or other factors useful ordesirable in performing information management operations. For example,a first cell may represent a geographic segment of an enterprise, suchas a Chicago office, and a second cell may represent a differentgeographic segment, such as a New York City office. Other cells mayrepresent departments within a particular office, e.g., human resources,finance, engineering, etc. Where delineated by function, a first cellmay perform one or more first types of information management operations(e.g., one or more first types of secondary copies at a certainfrequency), and a second cell may perform one or more second types ofinformation management operations (e.g., one or more second types ofsecondary copies at a different frequency and under different retentionrules). In general, the hierarchical information is maintained by one ormore storage managers 140 that manage the respective cells (e.g., incorresponding management database(s) 146).

Data Agents

A variety of different applications 110 can operate on a given clientcomputing device 102, including operating systems, file systems,database applications, e-mail applications, and virtual machines, justto name a few. And, as part of the process of creating and restoringsecondary copies 116, the client computing device 102 may be tasked withprocessing and preparing the primary data 112 generated by these variousapplications 110. Moreover, the nature of the processing/preparation candiffer across application types, e.g., due to inherent structural,state, and formatting differences among applications 110 and/or theoperating system of client computing device 102. Each data agent 142 istherefore advantageously configured in some embodiments to assist in theperformance of information management operations based on the type ofdata that is being protected at a client-specific and/orapplication-specific level.

Data agent 142 is a component of information system 100 and is generallydirected by storage manager 140 to participate in creating or restoringsecondary copies 116. Data agent 142 may be a software program (e.g., inthe form of a set of executable binary files) that executes on the sameclient computing device 102 as the associated application 110 that dataagent 142 is configured to protect. Data agent 142 is generallyresponsible for managing, initiating, or otherwise assisting in theperformance of information management operations in reference to itsassociated application(s) 110 and corresponding primary data 112 whichis generated/accessed by the particular application(s) 110. Forinstance, data agent 142 may take part in copying, archiving, migrating,and/or replicating of certain primary data 112 stored in the primarystorage device(s) 104. Data agent 142 may receive control informationfrom storage manager 140, such as commands to transfer copies of dataobjects and/or metadata to one or more media agents 144. Data agent 142also may compress, deduplicate, and encrypt certain primary data 112, aswell as capture application-related metadata before transmitting theprocessed data to media agent 144. Data agent 142 also may receiveinstructions from storage manager 140 to restore (or assist inrestoring) a secondary copy 116 from secondary storage device 108 toprimary storage 104, such that the restored data may be properlyaccessed by application 110 in a suitable format as though it wereprimary data 112.

Each data agent 142 may be specialized for a particular application 110.For instance, different individual data agents 142 may be designed tohandle Microsoft Exchange data, Lotus Notes data, Microsoft Windows filesystem data, Microsoft Active Directory Objects data, SQL Server data,SharePoint data, Oracle database data, SAP database data, virtualmachines and/or associated data, and other types of data. A file systemdata agent, for example, may handle data files and/or other file systeminformation. If a client computing device 102 has two or more types ofdata 112, a specialized data agent 142 may be used for each data type.For example, to backup, migrate, and/or restore all of the data on aMicrosoft Exchange server, the client computing device 102 may use: (1)a Microsoft Exchange Mailbox data agent 142 to back up the Exchangemailboxes; (2) a Microsoft Exchange Database data agent 142 to back upthe Exchange databases; (3) a Microsoft Exchange Public Folder dataagent 142 to back up the Exchange Public Folders; and (4) a MicrosoftWindows File System data agent 142 to back up the file system of clientcomputing device 102. In this example, these specialized data agents 142are treated as four separate data agents 142 even though they operate onthe same client computing device 102. Other examples may include archivemanagement data agents such as a migration archiver or a compliancearchiver, Quick Recovery® agents, and continuous data replicationagents. Application-specific data agents 142 can provide improvedperformance as compared to generic agents. For instance, becauseapplication-specific data agents 142 may only handle data for a singlesoftware application, the design, operation, and performance of the dataagent 142 can be streamlined. The data agent 142 may therefore executefaster and consume less persistent storage and/or operating memory thandata agents designed to generically accommodate multiple differentsoftware applications 110.

Each data agent 142 may be configured to access data and/or metadatastored in the primary storage device(s) 104 associated with data agent142 and its host client computing device 102, and process the dataappropriately. For example, during a secondary copy operation, dataagent 142 may arrange or assemble the data and metadata into one or morefiles having a certain format (e.g., a particular backup or archiveformat) before transferring the file(s) to a media agent 144 or othercomponent. The file(s) may include a list of files or other metadata. Insome embodiments, a data agent 142 may be distributed between clientcomputing device 102 and storage manager 140 (and any other intermediatecomponents) or may be deployed from a remote location or its functionsapproximated by a remote process that performs some or all of thefunctions of data agent 142. In addition, a data agent 142 may performsome functions provided by media agent 144. Other embodiments may employone or more generic data agents 142 that can handle and process datafrom two or more different applications 110, or that can handle andprocess multiple data types, instead of or in addition to usingspecialized data agents 142. For example, one generic data agent 142 maybe used to back up, migrate and restore Microsoft Exchange Mailbox dataand Microsoft Exchange Database data, while another generic data agentmay handle Microsoft Exchange Public Folder data and Microsoft WindowsFile System data.

Media Agents

As noted, off-loading certain responsibilities from client computingdevices 102 to intermediate components such as secondary storagecomputing device(s) 106 and corresponding media agent(s) 144 can providea number of benefits including improved performance of client computingdevice 102, faster and more reliable information management operations,and enhanced scalability. In one example which will be discussed furtherbelow, media agent 144 can act as a local cache of recently-copied dataand/or metadata stored to secondary storage device(s) 108, thusimproving restore capabilities and performance for the cached data.

Media agent 144 is a component of system 100 and is generally directedby storage manager 140 in creating and restoring secondary copies 116.Whereas storage manager 140 generally manages system 100 as a whole,media agent 144 provides a portal to certain secondary storage devices108, such as by having specialized features for communicating with andaccessing certain associated secondary storage device 108. Media agent144 may be a software program (e.g., in the form of a set of executablebinary files) that executes on a secondary storage computing device 106.Media agent 144 generally manages, coordinates, and facilitates thetransmission of data between a data agent 142 (executing on clientcomputing device 102) and secondary storage device(s) 108 associatedwith media agent 144. For instance, other components in the system mayinteract with media agent 144 to gain access to data stored onassociated secondary storage device(s) 108, (e.g., to browse, read,write, modify, delete, or restore data). Moreover, media agents 144 cangenerate and store information relating to characteristics of the storeddata and/or metadata, or can generate and store other types ofinformation that generally provides insight into the contents of thesecondary storage devices 108—generally referred to as indexing of thestored secondary copies 116. Each media agent 144 may operate on adedicated secondary storage computing device 106, while in otherembodiments a plurality of media agents 144 may operate on the samesecondary storage computing device 106.

A media agent 144 may be associated with a particular secondary storagedevice 108 if that media agent 144 is capable of one or more of: routingand/or storing data to the particular secondary storage device 108;coordinating the routing and/or storing of data to the particularsecondary storage device 108; retrieving data from the particularsecondary storage device 108; coordinating the retrieval of data fromthe particular secondary storage device 108; and modifying and/ordeleting data retrieved from the particular secondary storage device108. Media agent 144 in certain embodiments is physically separate fromthe associated secondary storage device 108. For instance, a media agent144 may operate on a secondary storage computing device 106 in adistinct housing, package, and/or location from the associated secondarystorage device 108. In one example, a media agent 144 operates on afirst server computer and is in communication with a secondary storagedevice(s) 108 operating in a separate rack-mounted RAID-based system.

A media agent 144 associated with a particular secondary storage device108 may instruct secondary storage device 108 to perform an informationmanagement task. For instance, a media agent 144 may instruct a tapelibrary to use a robotic arm or other retrieval means to load or eject acertain storage media, and to subsequently archive, migrate, or retrievedata to or from that media, e.g., for the purpose of restoring data to aclient computing device 102. As another example, a secondary storagedevice 108 may include an array of hard disk drives or solid statedrives organized in a RAID configuration, and media agent 144 mayforward a logical unit number (LUN) and other appropriate information tothe array, which uses the received information to execute the desiredsecondary copy operation. Media agent 144 may communicate with asecondary storage device 108 via a suitable communications link, such asa SCSI or Fibre Channel link.

Each media agent 144 may maintain an associated media agent database152. Media agent database 152 may be stored to a disk or other storagedevice (not shown) that is local to the secondary storage computingdevice 106 on which media agent 144 executes. In other cases, mediaagent database 152 is stored separately from the host secondary storagecomputing device 106. Media agent database 152 can include, among otherthings, a media agent index 153 (see, e.g., FIG. 1C). In some cases,media agent index 153 does not form a part of and is instead separatefrom media agent database 152.

Media agent index 153 (or “index 153”) may be a data structureassociated with the particular media agent 144 that includes informationabout the stored data associated with the particular media agent andwhich may be generated in the course of performing a secondary copyoperation or a restore. Index 153 provides a fast and efficientmechanism for locating/browsing secondary copies 116 or other datastored in secondary storage devices 108 without having to accesssecondary storage device 108 to retrieve the information from there. Forinstance, for each secondary copy 116, index 153 may include metadatasuch as a list of the data objects (e.g., files/subdirectories, databaseobjects, mailbox objects, etc.), a logical path to the secondary copy116 on the corresponding secondary storage device 108, locationinformation (e.g., offsets) indicating where the data objects are storedin the secondary storage device 108, when the data objects were createdor modified, etc. Thus, index 153 includes metadata associated with thesecondary copies 116 that is readily available for use from media agent144. In some embodiments, some or all of the information in index 153may instead or additionally be stored along with secondary copies 116 insecondary storage device 108. In some embodiments, a secondary storagedevice 108 can include sufficient information to enable a “bare metalrestore,” where the operating system and/or software applications of afailed client computing device 102 or another target may beautomatically restored without manually reinstalling individual softwarepackages (including operating systems).

Because index 153 may operate as a cache, it can also be referred to asan “index cache.” In such cases, information stored in index cache 153typically comprises data that reflects certain particulars aboutrelatively recent secondary copy operations. After some triggeringevent, such as after some time elapses or index cache 153 reaches aparticular size, certain portions of index cache 153 may be copied ormigrated to secondary storage device 108, e.g., on a least-recently-usedbasis. This information may be retrieved and uploaded back into indexcache 153 or otherwise restored to media agent 144 to facilitateretrieval of data from the secondary storage device(s) 108. In someembodiments, the cached information may include format orcontainerization information related to archives or other files storedon storage device(s) 108.

In some alternative embodiments media agent 144 generally acts as acoordinator or facilitator of secondary copy operations between clientcomputing devices 102 and secondary storage devices 108, but does notactually write the data to secondary storage device 108. For instance,storage manager 140 (or media agent 144) may instruct a client computingdevice 102 and secondary storage device 108 to communicate with oneanother directly. In such a case, client computing device 102 transmitsdata directly or via one or more intermediary components to secondarystorage device 108 according to the received instructions, and viceversa. Media agent 144 may still receive, process, and/or maintainmetadata related to the secondary copy operations, i.e., may continue tobuild and maintain index 153. In these embodiments, payload data canflow through media agent 144 for the purposes of populating index 153,but not for writing to secondary storage device 108. Media agent 144and/or other components such as storage manager 140 may in some casesincorporate additional functionality, such as data classification,content indexing, deduplication, encryption, compression, and the like.Further details regarding these and other functions are described below.

Distributed, Scalable Architecture

As described, certain functions of system 100 can be distributed amongstvarious physical and/or logical components. For instance, one or more ofstorage manager 140, data agents 142, and media agents 144 may operateon computing devices that are physically separate from one another. Thisarchitecture can provide a number of benefits. For instance, hardwareand software design choices for each distributed component can betargeted to suit its particular function. The secondary computingdevices 106 on which media agents 144 operate can be tailored forinteraction with associated secondary storage devices 108 and providefast index cache operation, among other specific tasks. Similarly,client computing device(s) 102 can be selected to effectively serviceapplications 110 in order to efficiently produce and store primary data112.

Moreover, in some cases, one or more of the individual components ofinformation management system 100 can be distributed to multipleseparate computing devices. As one example, for large file systems wherethe amount of data stored in management database 146 is relativelylarge, database 146 may be migrated to or may otherwise reside on aspecialized database server (e.g., an SQL server) separate from a serverthat implements the other functions of storage manager 140. Thisdistributed configuration can provide added protection because database146 can be protected with standard database utilities (e.g., SQL logshipping or database replication) independent from other functions ofstorage manager 140. Database 146 can be efficiently replicated to aremote site for use in the event of a disaster or other data loss at theprimary site. Or database 146 can be replicated to another computingdevice within the same site, such as to a higher performance machine inthe event that a storage manager host computing device can no longerservice the needs of a growing system 100.

The distributed architecture also provides scalability and efficientcomponent utilization. FIG. 1D shows an embodiment of informationmanagement system 100 including a plurality of client computing devices102 and associated data agents 142 as well as a plurality of secondarystorage computing devices 106 and associated media agents 144.Additional components can be added or subtracted based on the evolvingneeds of system 100. For instance, depending on where bottlenecks areidentified, administrators can add additional client computing devices102, secondary storage computing devices 106, and/or secondary storagedevices 108. Moreover, where multiple fungible components are available,load balancing can be implemented to dynamically address identifiedbottlenecks. As an example, storage manager 140 may dynamically selectwhich media agents 144 and/or secondary storage devices 108 to use forstorage operations based on a processing load analysis of media agents144 and/or secondary storage devices 108, respectively.

Where system 100 includes multiple media agents 144 (see, e.g., FIG.1D), a first media agent 144 may provide failover functionality for asecond failed media agent 144. In addition, media agents 144 can bedynamically selected to provide load balancing. Each client computingdevice 102 can communicate with, among other components, any of themedia agents 144, e.g., as directed by storage manager 140. And eachmedia agent 144 may communicate with, among other components, any ofsecondary storage devices 108, e.g., as directed by storage manager 140.Thus, operations can be routed to secondary storage devices 108 in adynamic and highly flexible manner, to provide load balancing, failover,etc. Further examples of scalable systems capable of dynamic storageoperations, load balancing, and failover are provided in U.S. Pat. No.7,246,207.

While distributing functionality amongst multiple computing devices canhave certain advantages, in other contexts it can be beneficial toconsolidate functionality on the same computing device. In alternativeconfigurations, certain components may reside and execute on the samecomputing device. As such, in other embodiments, one or more of thecomponents shown in FIG. 1C may be implemented on the same computingdevice. In one configuration, a storage manager 140, one or more dataagents 142, and/or one or more media agents 144 are all implemented onthe same computing device. In other embodiments, one or more data agents142 and one or more media agents 144 are implemented on the samecomputing device, while storage manager 140 is implemented on a separatecomputing device, etc. without limitation.

Exemplary Types of Information Management Operations, Including StorageOperations

In order to protect and leverage stored data, system 100 can beconfigured to perform a variety of information management operations,which may also be referred to in some cases as storage managementoperations or storage operations. These operations can generally include(i) data movement operations, (ii) processing and data manipulationoperations, and (iii) analysis, reporting, and management operations.

Data Movement Operations, Including Secondary Copy Operations

Data movement operations are generally storage operations that involvethe copying or migration of data between different locations in system100. For example, data movement operations can include operations inwhich stored data is copied, migrated, or otherwise transferred from oneor more first storage devices to one or more second storage devices,such as from primary storage device(s) 104 to secondary storagedevice(s) 108, from secondary storage device(s) 108 to differentsecondary storage device(s) 108, from secondary storage devices 108 toprimary storage devices 104, or from primary storage device(s) 104 todifferent primary storage device(s) 104, or in some cases within thesame primary storage device 104 such as within a storage array.

Data movement operations can include by way of example, backupoperations, archive operations, information lifecycle managementoperations such as hierarchical storage management operations,replication operations (e.g., continuous data replication), snapshotoperations, deduplication or single-instancing operations, auxiliarycopy operations, disaster-recovery copy operations, and the like. Aswill be discussed, some of these operations do not necessarily createdistinct copies. Nonetheless, some or all of these operations aregenerally referred to as “secondary copy operations” for simplicity,because they involve secondary copies. Data movement also comprisesrestoring secondary copies.

Backup Operations

A backup operation creates a copy of a version of primary data 112 at aparticular point in time (e.g., one or more files or other data units).Each subsequent backup copy 116 (which is a form of secondary copy 116)may be maintained independently of the first. A backup generallyinvolves maintaining a version of the copied primary data 112 as well asbackup copies 116. Further, a backup copy in some embodiments isgenerally stored in a form that is different from the native format,e.g., a backup format. This contrasts to the version in primary data 112which may instead be stored in a format native to the sourceapplication(s) 110. In various cases, backup copies can be stored in aformat in which the data is compressed, encrypted, deduplicated, and/orotherwise modified from the original native application format. Forexample, a backup copy may be stored in a compressed backup format thatfacilitates efficient long-term storage. Backup copies 116 can haverelatively long retention periods as compared to primary data 112, whichis generally highly changeable. Backup copies 116 may be stored on mediawith slower retrieval times than primary storage device 104. Some backupcopies may have shorter retention periods than some other types ofsecondary copies 116, such as archive copies (described below). Backupsmay be stored at an offsite location.

Backup operations can include full backups, differential backups,incremental backups, “synthetic full” backups, and/or creating a“reference copy.” A full backup (or “standard full backup”) in someembodiments is generally a complete image of the data to be protected.However, because full backup copies can consume a relatively largeamount of storage, it can be useful to use a full backup copy as abaseline and only store changes relative to the full backup copyafterwards.

A differential backup operation (or cumulative incremental backupoperation) tracks and stores changes that occurred since the last fullbackup. Differential backups can grow quickly in size, but can restorerelatively efficiently because a restore can be completed in some casesusing only the full backup copy and the latest differential copy.

An incremental backup operation generally tracks and stores changessince the most recent backup copy of any type, which can greatly reducestorage utilization. In some cases, however, restoring can be lengthycompared to full or differential backups because completing a restoreoperation may involve accessing a full backup in addition to multipleincremental backups.

Synthetic full backups generally consolidate data without directlybacking up data from the client computing device. A synthetic fullbackup is created from the most recent full backup (i.e., standard orsynthetic) and subsequent incremental and/or differential backups. Theresulting synthetic full backup is identical to what would have beencreated had the last backup for the subclient been a standard fullbackup. Unlike standard full, incremental, and differential backups,however, a synthetic full backup does not actually transfer data fromprimary storage to the backup media, because it operates as a backupconsolidator. A synthetic full backup extracts the index data of eachparticipating subclient. Using this index data and the previously backedup user data images, it builds new full backup images (e.g., bitmaps),one for each subclient. The new backup images consolidate the index anduser data stored in the related incremental, differential, and previousfull backups into a synthetic backup file that fully represents thesubclient (e.g., via pointers) but does not comprise all its constituentdata.

Any of the above types of backup operations can be at the volume level,file level, or block level. Volume level backup operations generallyinvolve copying of a data volume (e.g., a logical disk or partition) asa whole. In a file-level backup, information management system 100generally tracks changes to individual files and includes copies offiles in the backup copy. For block-level backups, files are broken intoconstituent blocks, and changes are tracked at the block level. Uponrestore, system 100 reassembles the blocks into files in a transparentfashion. Far less data may actually be transferred and copied tosecondary storage devices 108 during a file-level copy than avolume-level copy. Likewise, a block-level copy may transfer less datathan a file-level copy, resulting in faster execution. However,restoring a relatively higher-granularity copy can result in longerrestore times. For instance, when restoring a block-level copy, theprocess of locating and retrieving constituent blocks can sometimes takelonger than restoring file-level backups.

A reference copy may comprise copy(ies) of selected objects from backedup data, typically to help organize data by keeping contextualinformation from multiple sources together, and/or help retain specificdata for a longer period of time, such as for legal hold needs. Areference copy generally maintains data integrity, and when the data isrestored, it may be viewed in the same format as the source data. Insome embodiments, a reference copy is based on a specialized client,individual subclient and associated information management policies(e.g., storage policy, retention policy, etc.) that are administeredwithin system 100.

Archive Operations

Because backup operations generally involve maintaining a version of thecopied primary data 112 and also maintaining backup copies in secondarystorage device(s) 108, they can consume significant storage capacity. Toreduce storage consumption, an archive operation according to certainembodiments creates an archive copy 116 by both copying and removingsource data. Or, seen another way, archive operations can involve movingsome or all of the source data to the archive destination. Thus, datasatisfying criteria for removal (e.g., data of a threshold age or size)may be removed from source storage. The source data may be primary data112 or a secondary copy 116, depending on the situation. As with backupcopies, archive copies can be stored in a format in which the data iscompressed, encrypted, deduplicated, and/or otherwise modified from theformat of the original application or source copy. In addition, archivecopies may be retained for relatively long periods of time (e.g., years)and, in some cases are never deleted. In certain embodiments, archivecopies may be made and kept for extended periods in order to meetcompliance regulations.

Archiving can also serve the purpose of freeing up space in primarystorage device(s) 104 and easing the demand on computational resourceson client computing device 102. Similarly, when a secondary copy 116 isarchived, the archive copy can therefore serve the purpose of freeing upspace in the source secondary storage device(s) 108. Examples of dataarchiving operations are provided in U.S. Pat. No. 7,107,298.

Snapshot Operations

Snapshot operations can provide a relatively lightweight, efficientmechanism for protecting data. From an end-user viewpoint, a snapshotmay be thought of as an “instant” image of primary data 112 at a givenpoint in time, and may include state and/or status information relativeto an application 110 that creates/manages primary data 112. In oneembodiment, a snapshot may generally capture the directory structure ofan object in primary data 112 such as a file or volume or other data setat a particular moment in time and may also preserve file attributes andcontents. A snapshot in some cases is created relatively quickly, e.g.,substantially instantly, using a minimum amount of file space, but maystill function as a conventional file system backup.

A “hardware snapshot” (or “hardware-based snapshot”) operation occurswhere a target storage device (e.g., a primary storage device 104 or asecondary storage device 108) performs the snapshot operation in aself-contained fashion, substantially independently, using hardware,firmware and/or software operating on the storage device itself. Forinstance, the storage device may perform snapshot operations generallywithout intervention or oversight from any of the other components ofthe system 100, e.g., a storage array may generate an “array-created”hardware snapshot and may also manage its storage, integrity,versioning, etc. In this manner, hardware snapshots can off-load othercomponents of system 100 from snapshot processing. An array may receivea request from another component to take a snapshot and then proceed toexecute the “hardware snapshot” operations autonomously, preferablyreporting success to the requesting component.

A “software snapshot” (or “software-based snapshot”) operation, on theother hand, occurs where a component in system 100 (e.g., clientcomputing device 102, etc.) implements a software layer that manages thesnapshot operation via interaction with the target storage device. Forinstance, the component executing the snapshot management software layermay derive a set of pointers and/or data that represents the snapshot.The snapshot management software layer may then transmit the same to thetarget storage device, along with appropriate instructions for writingthe snapshot. One example of a software snapshot product is MicrosoftVolume Snapshot Service (VSS), which is part of the Microsoft Windowsoperating system.

Some types of snapshots do not actually create another physical copy ofall the data as it existed at the particular point in time, but maysimply create pointers that map files and directories to specific memorylocations (e.g., to specific disk blocks) where the data resides as itexisted at the particular point in time. For example, a snapshot copymay include a set of pointers derived from the file system or from anapplication. In some other cases, the snapshot may be created at theblock-level, such that creation of the snapshot occurs without awarenessof the file system. Each pointer points to a respective stored datablock, so that collectively, the set of pointers reflect the storagelocation and state of the data object (e.g., file(s) or volume(s) ordata set(s)) at the point in time when the snapshot copy was created.

An initial snapshot may use only a small amount of disk space needed torecord a mapping or other data structure representing or otherwisetracking the blocks that correspond to the current state of the filesystem. Additional disk space is usually required only when files anddirectories change later on. Furthermore, when files change, typicallyonly the pointers which map to blocks are copied, not the blocksthemselves. For example for “copy-on-write” snapshots, when a blockchanges in primary storage, the block is copied to secondary storage orcached in primary storage before the block is overwritten in primarystorage, and the pointer to that block is changed to reflect the newlocation of that block. The snapshot mapping of file system data mayalso be updated to reflect the changed block(s) at that particular pointin time. In some other cases, a snapshot includes a full physical copyof all or substantially all of the data represented by the snapshot.Further examples of snapshot operations are provided in U.S. Pat. No.7,529,782. A snapshot copy in many cases can be made quickly and withoutsignificantly impacting primary computing resources because largeamounts of data need not be copied or moved. In some embodiments, asnapshot may exist as a virtual file system, parallel to the actual filesystem. Users in some cases gain read-only access to the record of filesand directories of the snapshot. By electing to restore primary data 112from a snapshot taken at a given point in time, users may also returnthe current file system to the state of the file system that existedwhen the snapshot was taken.

Replication Operations

Replication is another type of secondary copy operation. Some types ofsecondary copies 116 periodically capture images of primary data 112 atparticular points in time (e.g., backups, archives, and snapshots).However, it can also be useful for recovery purposes to protect primarydata 112 in a more continuous fashion, by replicating primary data 112substantially as changes occur. In some cases a replication copy can bea mirror copy, for instance, where changes made to primary data 112 aremirrored or substantially immediately copied to another location (e.g.,to secondary storage device(s) 108). By copying each write operation tothe replication copy, two storage systems are kept synchronized orsubstantially synchronized so that they are virtually identical atapproximately the same time. Where entire disk volumes are mirrored,however, mirroring can require significant amount of storage space andutilizes a large amount of processing resources.

According to some embodiments, secondary copy operations are performedon replicated data that represents a recoverable state, or “known goodstate” of a particular application running on the source system. Forinstance, in certain embodiments, known good replication copies may beviewed as copies of primary data 112. This feature allows the system todirectly access, copy, restore, back up, or otherwise manipulate thereplication copies as if they were the “live” primary data 112. This canreduce access time, storage utilization, and impact on sourceapplications 110, among other benefits. Based on known good stateinformation, system 100 can replicate sections of application data thatrepresent a recoverable state rather than rote copying of blocks ofdata. Examples of replication operations (e.g., continuous datareplication) are provided in U.S. Pat. No. 7,617,262.

Deduplication/Single-Instancing Operations

Deduplication or single-instance storage is useful to reduce the amountof non-primary data. For instance, some or all of the above-describedsecondary copy operations can involve deduplication in some fashion. Newdata is read, broken down into data portions of a selected granularity(e.g., sub-file level blocks, files, etc.), compared with correspondingportions that are already in secondary storage, and only new/changedportions are stored. Portions that already exist are represented aspointers to the already-stored data. Thus, a deduplicated secondary copy116 may comprise actual data portions copied from primary data 112 andmay further comprise pointers to already-stored data, which is generallymore storage-efficient than a full copy.

In order to streamline the comparison process, system 100 may calculateand/or store signatures (e.g., hashes or cryptographically unique IDs)corresponding to the individual source data portions and compare thesignatures to already-stored data signatures, instead of comparingentire data portions. In some cases, only a single instance of each dataportion is stored, and deduplication operations may therefore bereferred to interchangeably as “single-instancing” operations. Dependingon the implementation, however, deduplication operations can store morethan one instance of certain data portions, yet still significantlyreduce stored-data redundancy. Depending on the embodiment,deduplication portions such as data blocks can be of fixed or variablelength. Using variable length blocks can enhance deduplication byresponding to changes in the data stream, but can involve more complexprocessing. In some cases, system 100 utilizes a technique fordynamically aligning deduplication blocks based on changing content inthe data stream, as described in U.S. Pat. No. 8,364,652.

System 100 can deduplicate in a variety of manners at a variety oflocations. For instance, in some embodiments, system 100 implements“target-side” deduplication by deduplicating data at the media agent 144after being received from data agent 142. In some such cases, mediaagents 144 are generally configured to manage the deduplication process.For instance, one or more of the media agents 144 maintain acorresponding deduplication database that stores deduplicationinformation (e.g., datablock signatures). Examples of such aconfiguration are provided in U.S. Pat. No. 9,020,900. Instead of or incombination with “target-side” deduplication, “source-side” (or“client-side”) deduplication can also be performed, e.g., to reduce theamount of data to be transmitted by data agent 142 to media agent 144.Storage manager 140 may communicate with other components within system100 via network protocols and cloud service provider APIs to facilitatecloud-based deduplication/single instancing, as exemplified in U.S. Pat.No. 8,954,446. Some other deduplication/single instancing techniques aredescribed in U.S. Pat. Pub. No. 2006/0224846 and in U.S. Pat. No.9,098,495.

Information Lifecycle Management and Hierarchical Storage Management

In some embodiments, files and other data over their lifetime move frommore expensive quick-access storage to less expensive slower-accessstorage. Operations associated with moving data through various tiers ofstorage are sometimes referred to as information lifecycle management(ILM) operations.

One type of ILM operation is a hierarchical storage management (HSM)operation, which generally automatically moves data between classes ofstorage devices, such as from high-cost to low-cost storage devices. Forinstance, an HSM operation may involve movement of data from primarystorage devices 104 to secondary storage devices 108, or between tiersof secondary storage devices 108. With each tier, the storage devicesmay be progressively cheaper, have relatively slower access/restoretimes, etc. For example, movement of data between tiers may occur asdata becomes less important over time. In some embodiments, an HSMoperation is similar to archiving in that creating an HSM copy may(though not always) involve deleting some of the source data, e.g.,according to one or more criteria related to the source data. Forexample, an HSM copy may include primary data 112 or a secondary copy116 that exceeds a given size threshold or a given age threshold. Often,and unlike some types of archive copies, HSM data that is removed oraged from the source is replaced by a logical reference pointer or stub.The reference pointer or stub can be stored in the primary storagedevice 104 or other source storage device, such as a secondary storagedevice 108 to replace the deleted source data and to point to orotherwise indicate the new location in (another) secondary storagedevice 108.

For example, files are generally moved between higher and lower coststorage depending on how often the files are accessed. When a userrequests access to HSM data that has been removed or migrated, system100 uses the stub to locate the data and may make recovery of the dataappear transparent, even though the HSM data may be stored at a locationdifferent from other source data. In this manner, the data appears tothe user (e.g., in file system browsing windows and the like) as if itstill resides in the source location (e.g., in a primary storage device104). The stub may include metadata associated with the correspondingdata, so that a file system and/or application can provide someinformation about the data object and/or a limited-functionality version(e.g., a preview) of the data object.

An HSM copy may be stored in a format other than the native applicationformat (e.g., compressed, encrypted, deduplicated, and/or otherwisemodified). In some cases, copies which involve the removal of data fromsource storage and the maintenance of stub or other logical referenceinformation on source storage may be referred to generally as “on-linearchive copies.” On the other hand, copies which involve the removal ofdata from source storage without the maintenance of stub or otherlogical reference information on source storage may be referred to as“off-line archive copies.” Examples of HSM and ILM techniques areprovided in U.S. Pat. No. 7,343,453.

Auxiliary Copy Operations

An auxiliary copy is generally a copy of an existing secondary copy 116.For instance, an initial secondary copy 116 may be derived from primarydata 112 or from data residing in secondary storage subsystem 118,whereas an auxiliary copy is generated from the initial secondary copy116. Auxiliary copies provide additional standby copies of data and mayreside on different secondary storage devices 108 than the initialsecondary copies 116. Thus, auxiliary copies can be used for recoverypurposes if initial secondary copies 116 become unavailable. Exemplaryauxiliary copy techniques are described in further detail in U.S. Pat.No. 8,230,195.

Disaster-Recovery Copy Operations

System 100 may also make and retain disaster recovery copies, often assecondary, high-availability disk copies. System 100 may createsecondary copies and store them at disaster recovery locations usingauxiliary copy or replication operations, such as continuous datareplication technologies. Depending on the particular data protectiongoals, disaster recovery locations can be remote from the clientcomputing devices 102 and primary storage devices 104, remote from someor all of the secondary storage devices 108, or both.

Data Manipulation, Including Encryption and Compression

Data manipulation and processing may include encryption and compressionas well as integrity marking and checking, formatting for transmission,formatting for storage, etc. Data may be manipulated “client-side” bydata agent 142 as well as “target-side” by media agent 144 in the courseof creating secondary copy 116, or conversely in the course of restoringdata from secondary to primary.

Encryption Operations

System 100 in some cases is configured to process data (e.g., files orother data objects, primary data 112, secondary copies 116, etc.),according to an appropriate encryption algorithm (e.g., Blowfish,Advanced Encryption Standard (AES), Triple Data Encryption Standard(3-DES), etc.) to limit access and provide data security. System 100 insome cases encrypts the data at the client level, such that clientcomputing devices 102 (e.g., data agents 142) encrypt the data prior totransferring it to other components, e.g., before sending the data tomedia agents 144 during a secondary copy operation. In such cases,client computing device 102 may maintain or have access to an encryptionkey or passphrase for decrypting the data upon restore. Encryption canalso occur when media agent 144 creates auxiliary copies or archivecopies. Encryption may be applied in creating a secondary copy 116 of apreviously unencrypted secondary copy 116, without limitation. Infurther embodiments, secondary storage devices 108 can implementbuilt-in, high performance hardware-based encryption.

Compression Operations

Similar to encryption, system 100 may also or alternatively compressdata in the course of generating a secondary copy 116. Compressionencodes information such that fewer bits are needed to represent theinformation as compared to the original representation. Compressiontechniques are well known in the art. Compression operations may applyone or more data compression algorithms. Compression may be applied increating a secondary copy 116 of a previously uncompressed secondarycopy, e.g., when making archive copies or disaster recovery copies. Theuse of compression may result in metadata that specifies the nature ofthe compression, so that data may be uncompressed on restore ifappropriate.

Data Analysis, Reporting, and Management Operations

Data analysis, reporting, and management operations can differ from datamovement operations in that they do not necessarily involve copying,migration or other transfer of data between different locations in thesystem. For instance, data analysis operations may involve processing(e.g., offline processing) or modification of already stored primarydata 112 and/or secondary copies 116. However, in some embodiments dataanalysis operations are performed in conjunction with data movementoperations. Some data analysis operations include content indexingoperations and classification operations which can be useful inleveraging data under management to enhance search and other features.

Classification Operations/Content Indexing

In some embodiments, information management system 100 analyzes andindexes characteristics, content, and metadata associated with primarydata 112 (“online content indexing”) and/or secondary copies 116(“off-line content indexing”). Content indexing can identify files orother data objects based on content (e.g., user-defined keywords orphrases, other keywords/phrases that are not defined by a user, etc.),and/or metadata (e.g., email metadata such as “to,” “from,” “cc,” “bcc,”attachment name, received time, etc.). Content indexes may be searchedand search results may be restored.

System 100 generally organizes and catalogues the results into a contentindex, which may be stored within media agent database 152, for example.The content index can also include the storage locations of or pointerreferences to indexed data in primary data 112 and/or secondary copies116. Results may also be stored elsewhere in system 100 (e.g., inprimary storage device 104 or in secondary storage device 108). Suchcontent index data provides storage manager 140 or other components withan efficient mechanism for locating primary data 112 and/or secondarycopies 116 of data objects that match particular criteria, thus greatlyincreasing the search speed capability of system 100. For instance,search criteria can be specified by a user through user interface 158 ofstorage manager 140. Moreover, when system 100 analyzes data and/ormetadata in secondary copies 116 to create an “off-line content index,”this operation has no significant impact on the performance of clientcomputing devices 102 and thus does not take a toll on the productionenvironment. Examples of content indexing techniques are provided inU.S. Pat. No. 8,170,995.

One or more components, such as a content index engine, can beconfigured to scan data and/or associated metadata for classificationpurposes to populate a database (or other data structure) ofinformation, which can be referred to as a “data classificationdatabase” or a “metabase.” Depending on the embodiment, the dataclassification database(s) can be organized in a variety of differentways, including centralization, logical sub-divisions, and/or physicalsub-divisions. For instance, one or more data classification databasesmay be associated with different subsystems or tiers within system 100.As an example, there may be a first metabase associated with primarystorage subsystem 117 and a second metabase associated with secondarystorage subsystem 118. In other cases, metabase(s) may be associatedwith individual components, e.g., client computing devices 102 and/ormedia agents 144. In some embodiments, a data classification databasemay reside as one or more data structures within management database146, may be otherwise associated with storage manager 140, and/or mayreside as a separate component. In some cases, metabase(s) may beincluded in separate database(s) and/or on separate storage device(s)from primary data 112 and/or secondary copies 116, such that operationsrelated to the metabase(s) do not significantly impact performance onother components of system 100. In other cases, metabase(s) may bestored along with primary data 112 and/or secondary copies 116. Files orother data objects can be associated with identifiers (e.g., tagentries, etc.) to facilitate searches of stored data objects. Among anumber of other benefits, the metabase can also allow efficient,automatic identification of files or other data objects to associatewith secondary copy or other information management operations. Forinstance, a metabase can dramatically improve the speed with whichsystem 100 can search through and identify data as compared to otherapproaches that involve scanning an entire file system. Examples ofmetabases and data classification operations are provided in U.S. Pat.Nos. 7,734,669 and 7,747,579.

Management and Reporting Operations

Certain embodiments leverage the integrated ubiquitous nature of system100 to provide useful system-wide management and reporting. Operationsmanagement can generally include monitoring and managing the health andperformance of system 100 by, without limitation, performing errortracking, generating granular storage/performance metrics (e.g., jobsuccess/failure information, deduplication efficiency, etc.), generatingstorage modeling and costing information, and the like. As an example,storage manager 140 or another component in system 100 may analyzetraffic patterns and suggest and/or automatically route data to minimizecongestion. In some embodiments, the system can generate predictionsrelating to storage operations or storage operation information. Suchpredictions, which may be based on a trending analysis, may predictvarious network operations or resource usage, such as network trafficlevels, storage media use, use of bandwidth of communication links, useof media agent components, etc. Further examples of traffic analysis,trend analysis, prediction generation, and the like are described inU.S. Pat. No. 7,343,453.

In some configurations having a hierarchy of storage operation cells, amaster storage manager 140 may track the status of subordinate cells,such as the status of jobs, system components, system resources, andother items, by communicating with storage managers 140 (or othercomponents) in the respective storage operation cells. Moreover, themaster storage manager 140 may also track status by receiving periodicstatus updates from the storage managers 140 (or other components) inthe respective cells regarding jobs, system components, systemresources, and other items. In some embodiments, a master storagemanager 140 may store status information and other information regardingits associated storage operation cells and other system information inits management database 146 and/or index 150 (or in another location).The master storage manager 140 or other component may also determinewhether certain storage-related or other criteria are satisfied, and mayperform an action or trigger event (e.g., data migration) in response tothe criteria being satisfied, such as where a storage threshold is metfor a particular volume, or where inadequate protection exists forcertain data. For instance, data from one or more storage operationcells is used to dynamically and automatically mitigate recognizedrisks, and/or to advise users of risks or suggest actions to mitigatethese risks. For example, an information management policy may specifycertain requirements (e.g., that a storage device should maintain acertain amount of free space, that secondary copies should occur at aparticular interval, that data should be aged and migrated to otherstorage after a particular period, that data on a secondary volumeshould always have a certain level of availability and be restorablewithin a given time period, that data on a secondary volume may bemirrored or otherwise migrated to a specified number of other volumes,etc.). If a risk condition or other criterion is triggered, the systemmay notify the user of these conditions and may suggest (orautomatically implement) a mitigation action to address the risk. Forexample, the system may indicate that data from a primary copy 112should be migrated to a secondary storage device 108 to free up space onprimary storage device 104. Examples of the use of risk factors andother triggering criteria are described in U.S. Pat. No. 7,343,453.

In some embodiments, system 100 may also determine whether a metric orother indication satisfies particular storage criteria sufficient toperform an action. For example, a storage policy or other definitionmight indicate that a storage manager 140 should initiate a particularaction if a storage metric or other indication drops below or otherwisefails to satisfy specified criteria such as a threshold of dataprotection. In some embodiments, risk factors may be quantified intocertain measurable service or risk levels. For example, certainapplications and associated data may be considered to be more importantrelative to other data and services. Financial compliance data, forexample, may be of greater importance than marketing materials, etc.Network administrators may assign priority values or “weights” tocertain data and/or applications corresponding to the relativeimportance. The level of compliance of secondary copy operationsspecified for these applications may also be assigned a certain value.Thus, the health, impact, and overall importance of a service may bedetermined, such as by measuring the compliance value and calculatingthe product of the priority value and the compliance value to determinethe “service level” and comparing it to certain operational thresholdsto determine whether it is acceptable. Further examples of the servicelevel determination are provided in U.S. Pat. No. 7,343,453.

System 100 may additionally calculate data costing and data availabilityassociated with information management operation cells. For instance,data received from a cell may be used in conjunction withhardware-related information and other information about system elementsto determine the cost of storage and/or the availability of particulardata. Exemplary information generated could include how fast aparticular department is using up available storage space, how long datawould take to recover over a particular pathway from a particularsecondary storage device, costs over time, etc. Moreover, in someembodiments, such information may be used to determine or predict theoverall cost associated with the storage of certain information. Thecost associated with hosting a certain application may be based, atleast in part, on the type of media on which the data resides, forexample. Storage devices may be assigned to a particular costcategories, for example. Further examples of costing techniques aredescribed in U.S. Pat. No. 7,343,453.

Any of the above types of information (e.g., information related totrending, predictions, job, cell or component status, risk, servicelevel, costing, etc.) can generally be provided to users via userinterface 158 in a single integrated view or console (not shown). Reporttypes may include: scheduling, event management, media management anddata aging. Available reports may also include backup history, dataaging history, auxiliary copy history, job history, library and drive,media in library, restore history, and storage policy, etc., withoutlimitation. Such reports may be specified and created at a certain pointin time as a system analysis, forecasting, or provisioning tool.Integrated reports may also be generated that illustrate storage andperformance metrics, risks and storage costing information. Moreover,users may create their own reports based on specific needs. Userinterface 158 can include an option to graphically depict the variouscomponents in the system using appropriate icons. As one example, userinterface 158 may provide a graphical depiction of primary storagedevices 104, secondary storage devices 108, data agents 142 and/or mediaagents 144, and their relationship to one another in system 100.

In general, the operations management functionality of system 100 canfacilitate planning and decision-making. For example, in someembodiments, a user may view the status of some or all jobs as well asthe status of each component of information management system 100. Usersmay then plan and make decisions based on this data. For instance, auser may view high-level information regarding secondary copy operationsfor system 100, such as job status, component status, resource status(e.g., communication pathways, etc.), and other information. The usermay also drill down or use other means to obtain more detailedinformation regarding a particular component, job, or the like. Furtherexamples are provided in U.S. Pat. No. 7,343,453.

System 100 can also be configured to perform system-wide e-discoveryoperations in some embodiments. In general, e-discovery operationsprovide a unified collection and search capability for data in thesystem, such as data stored in secondary storage devices 108 (e.g.,backups, archives, or other secondary copies 116). For example, system100 may construct and maintain a virtual repository for data stored insystem 100 that is integrated across source applications 110, differentstorage device types, etc. According to some embodiments, e-discoveryutilizes other techniques described herein, such as data classificationand/or content indexing.

Information Management Policies

An information management policy 148 can include a data structure orother information source that specifies a set of parameters (e.g.,criteria and rules) associated with secondary copy and/or otherinformation management operations.

One type of information management policy 148 is a “storage policy.”According to certain embodiments, a storage policy generally comprises adata structure or other information source that defines (or includesinformation sufficient to determine) a set of preferences or othercriteria for performing information management operations. Storagepolicies can include one or more of the following: (1) what data will beassociated with the storage policy, e.g., subclient; (2) a destinationto which the data will be stored; (3) datapath information specifyinghow the data will be communicated to the destination; (4) the type ofsecondary copy operation to be performed; and (5) retention informationspecifying how long the data will be retained at the destination (see,e.g., FIG. 1E). Data associated with a storage policy can be logicallyorganized into subclients, which may represent primary data 112 and/orsecondary copies 116. A subclient may represent static or dynamicassociations of portions of a data volume. Subclients may representmutually exclusive portions. Thus, in certain embodiments, a portion ofdata may be given a label and the association is stored as a staticentity in an index, database or other storage location. Subclients mayalso be used as an effective administrative scheme of organizing dataaccording to data type, department within the enterprise, storagepreferences, or the like. Depending on the configuration, subclients cancorrespond to files, folders, virtual machines, databases, etc. In oneexemplary scenario, an administrator may find it preferable to separatee-mail data from financial data using two different subclients.

A storage policy can define where data is stored by specifying a targetor destination storage device (or group of storage devices). Forinstance, where the secondary storage device 108 includes a group ofdisk libraries, the storage policy may specify a particular disk libraryfor storing the subclients associated with the policy. As anotherexample, where the secondary storage devices 108 include one or moretape libraries, the storage policy may specify a particular tape libraryfor storing the subclients associated with the storage policy, and mayalso specify a drive pool and a tape pool defining a group of tapedrives and a group of tapes, respectively, for use in storing thesubclient data. While information in the storage policy can bestatically assigned in some cases, some or all of the information in thestorage policy can also be dynamically determined based on criteria setforth in the storage policy. For instance, based on such criteria, aparticular destination storage device(s) or other parameter of thestorage policy may be determined based on characteristics associatedwith the data involved in a particular secondary copy operation, deviceavailability (e.g., availability of a secondary storage device 108 or amedia agent 144), network status and conditions (e.g., identifiedbottlenecks), user credentials, and the like.

Datapath information can also be included in the storage policy. Forinstance, the storage policy may specify network pathways and componentsto utilize when moving the data to the destination storage device(s). Insome embodiments, the storage policy specifies one or more media agents144 for conveying data associated with the storage policy between thesource and destination. A storage policy can also specify the type(s) ofassociated operations, such as backup, archive, snapshot, auxiliarycopy, or the like. Furthermore, retention parameters can specify howlong the resulting secondary copies 116 will be kept (e.g., a number ofdays, months, years, etc.), perhaps depending on organizational needsand/or compliance criteria.

When adding a new client computing device 102, administrators canmanually configure information management policies 148 and/or othersettings, e.g., via user interface 158. However, this can be an involvedprocess resulting in delays, and it may be desirable to begin dataprotection operations quickly, without awaiting human intervention.Thus, in some embodiments, system 100 automatically applies a defaultconfiguration to client computing device 102. As one example, when oneor more data agent(s) 142 are installed on a client computing device102, the installation script may register the client computing device102 with storage manager 140, which in turn applies the defaultconfiguration to the new client computing device 102. In this manner,data protection operations can begin substantially immediately. Thedefault configuration can include a default storage policy, for example,and can specify any appropriate information sufficient to begin dataprotection operations. This can include a type of data protectionoperation, scheduling information, a target secondary storage device108, data path information (e.g., a particular media agent 144), and thelike.

Another type of information management policy 148 is a “schedulingpolicy,” which specifies when and how often to perform operations.Scheduling parameters may specify with what frequency (e.g., hourly,weekly, daily, event-based, etc.) or under what triggering conditionssecondary copy or other information management operations are to takeplace. Scheduling policies in some cases are associated with particularcomponents, such as a subclient, client computing device 102, and thelike.

Another type of information management policy 148 is an “audit policy”(or “security policy”), which comprises preferences, rules and/orcriteria that protect sensitive data in system 100. For example, anaudit policy may define “sensitive objects” which are files or dataobjects that contain particular keywords (e.g., “confidential,” or“privileged”) and/or are associated with particular keywords (e.g., inmetadata) or particular flags (e.g., in metadata identifying a documentor email as personal, confidential, etc.). An audit policy may furtherspecify rules for handling sensitive objects. As an example, an auditpolicy may require that a reviewer approve the transfer of any sensitiveobjects to a cloud storage site, and that if approval is denied for aparticular sensitive object, the sensitive object should be transferredto a local primary storage device 104 instead. To facilitate thisapproval, the audit policy may further specify how a secondary storagecomputing device 106 or other system component should notify a reviewerthat a sensitive object is slated for transfer.

Another type of information management policy 148 is a “provisioningpolicy,” which can include preferences, priorities, rules, and/orcriteria that specify how client computing devices 102 (or groupsthereof) may utilize system resources, such as available storage oncloud storage and/or network bandwidth. A provisioning policy specifies,for example, data quotas for particular client computing devices 102(e.g., a number of gigabytes that can be stored monthly, quarterly orannually). Storage manager 140 or other components may enforce theprovisioning policy. For instance, media agents 144 may enforce thepolicy when transferring data to secondary storage devices 108. If aclient computing device 102 exceeds a quota, a budget for the clientcomputing device 102 (or associated department) may be adjustedaccordingly or an alert may trigger.

While the above types of information management policies 148 aredescribed as separate policies, one or more of these can be generallycombined into a single information management policy 148. For instance,a storage policy may also include or otherwise be associated with one ormore scheduling, audit, or provisioning policies or operationalparameters thereof. Moreover, while storage policies are typicallyassociated with moving and storing data, other policies may beassociated with other types of information management operations. Thefollowing is a non-exhaustive list of items that information managementpolicies 148 may specify:

-   -   schedules or other timing information, e.g., specifying when        and/or how often to perform information management operations;    -   the type of secondary copy 116 and/or copy format (e.g.,        snapshot, backup, archive, HSM, etc.);    -   a location or a class or quality of storage for storing        secondary copies 116 (e.g., one or more particular secondary        storage devices 108);    -   preferences regarding whether and how to encrypt, compress,        deduplicate, or otherwise modify or transform secondary copies        116;    -   which system components and/or network pathways (e.g., preferred        media agents 144) should be used to perform secondary storage        operations;    -   resource allocation among different computing devices or other        system components used in performing information management        operations (e.g., bandwidth allocation, available storage        capacity, etc.);    -   whether and how to synchronize or otherwise distribute files or        other data objects across multiple computing devices or hosted        services; and    -   retention information specifying the length of time primary data        112 and/or secondary copies 116 should be retained, e.g., in a        particular class or tier of storage devices, or within the        system 100.

Information management policies 148 can additionally specify or dependon historical or current criteria that may be used to determine whichrules to apply to a particular data object, system component, orinformation management operation, such as:

-   -   frequency with which primary data 112 or a secondary copy 116 of        a data object or metadata has been or is predicted to be used,        accessed, or modified;    -   time-related factors (e.g., aging information such as time since        the creation or modification of a data object);    -   deduplication information (e.g., hashes, data blocks,        deduplication block size, deduplication efficiency or other        metrics);    -   an estimated or historic usage or cost associated with different        components (e.g., with secondary storage devices 108);    -   the identity of users, applications 110, client computing        devices 102 and/or other computing devices that created,        accessed, modified, or otherwise utilized primary data 112 or        secondary copies 116;    -   a relative sensitivity (e.g., confidentiality, importance) of a        data object, e.g., as determined by its content and/or metadata;    -   the current or historical storage capacity of various storage        devices;    -   the current or historical network capacity of network pathways        connecting various components within the storage operation cell;    -   access control lists or other security information; and    -   the content of a particular data object (e.g., its textual        content) or of metadata associated with the data object.

Exemplary Storage Policy and Secondary Copy Operations

FIG. 1E includes a data flow diagram depicting performance of secondarycopy operations by an embodiment of information management system 100,according to an exemplary storage policy 148A. System 100 includes astorage manager 140, a client computing device 102 having a file systemdata agent 142A and an email data agent 142B operating thereon, aprimary storage device 104, two media agents 144A, 144B, and twosecondary storage devices 108: a disk library 108A and a tape library108B. As shown, primary storage device 104 includes primary data 112A,which is associated with a logical grouping of data associated with afile system (“file system subclient”), and primary data 112B, which is alogical grouping of data associated with email (“email subclient”). Thetechniques described with respect to FIG. 1E can be utilized inconjunction with data that is otherwise organized as well.

As indicated by the dashed box, the second media agent 144B and tapelibrary 108B are “off-site,” and may be remotely located from the othercomponents in system 100 (e.g., in a different city, office building,etc.). Indeed, “off-site” may refer to a magnetic tape located in remotestorage, which must be manually retrieved and loaded into a tape driveto be read. In this manner, information stored on the tape library 108Bmay provide protection in the event of a disaster or other failure atthe main site(s) where data is stored.

The file system subclient 112A in certain embodiments generallycomprises information generated by the file system and/or operatingsystem of client computing device 102, and can include, for example,file system data (e.g., regular files, file tables, mount points, etc.),operating system data (e.g., registries, event logs, etc.), and thelike. The e-mail subclient 112B can include data generated by an e-mailapplication operating on client computing device 102, e.g., mailboxinformation, folder information, emails, attachments, associateddatabase information, and the like. As described above, the subclientscan be logical containers, and the data included in the correspondingprimary data 112A and 112B may or may not be stored contiguously.

The exemplary storage policy 148A includes backup copy preferences orrule set 160, disaster recovery copy preferences or rule set 162, andcompliance copy preferences or rule set 164. Backup copy rule set 160specifies that it is associated with file system subclient 166 and emailsubclient 168. Each of subclients 166 and 168 are associated with theparticular client computing device 102. Backup copy rule set 160 furtherspecifies that the backup operation will be written to disk library 108Aand designates a particular media agent 144A to convey the data to disklibrary 108A. Finally, backup copy rule set 160 specifies that backupcopies created according to rule set 160 are scheduled to be generatedhourly and are to be retained for 30 days. In some other embodiments,scheduling information is not included in storage policy 148A and isinstead specified by a separate scheduling policy.

Disaster recovery copy rule set 162 is associated with the same twosubclients 166 and 168. However, disaster recovery copy rule set 162 isassociated with tape library 108B, unlike backup copy rule set 160.Moreover, disaster recovery copy rule set 162 specifies that a differentmedia agent, namely 144B, will convey data to tape library 108B.Disaster recovery copies created according to rule set 162 will beretained for 60 days and will be generated daily. Disaster recoverycopies generated according to disaster recovery copy rule set 162 canprovide protection in the event of a disaster or other catastrophic dataloss that would affect the backup copy 116A maintained on disk library108A.

Compliance copy rule set 164 is only associated with the email subclient168, and not the file system subclient 166. Compliance copies generatedaccording to compliance copy rule set 164 will therefore not includeprimary data 112A from the file system subclient 166. For instance, theorganization may be under an obligation to store and maintain copies ofemail data for a particular period of time (e.g., 10 years) to complywith state or federal regulations, while similar regulations do notapply to file system data. Compliance copy rule set 164 is associatedwith the same tape library 108B and media agent 144B as disasterrecovery copy rule set 162, although a different storage device or mediaagent could be used in other embodiments. Finally, compliance copy ruleset 164 specifies that the copies it governs will be generated quarterlyand retained for 10 years.

Secondary Copy Jobs

A logical grouping of secondary copy operations governed by a rule setand being initiated at a point in time may be referred to as a“secondary copy job” (and sometimes may be called a “backup job,” eventhough it is not necessarily limited to creating only backup copies).Secondary copy jobs may be initiated on demand as well. Steps 1-9 belowillustrate three secondary copy jobs based on storage policy 148A.

Referring to FIG. 1E, at step 1, storage manager 140 initiates a backupjob according to the backup copy rule set 160, which logically comprisesall the secondary copy operations necessary to effectuate rules 160 instorage policy 148A every hour, including steps 1-4 occurring hourly.For instance, a scheduling service running on storage manager 140accesses backup copy rule set 160 or a separate scheduling policyassociated with client computing device 102 and initiates a backup jobon an hourly basis. Thus, at the scheduled time, storage manager 140sends instructions to client computing device 102 (i.e., to both dataagent 142A and data agent 142B) to begin the backup job.

At step 2, file system data agent 142A and email data agent 142B onclient computing device 102 respond to instructions from storage manager140 by accessing and processing the respective subclient primary data112A and 112B involved in the backup copy operation, which can be foundin primary storage device 104. Because the secondary copy operation is abackup copy operation, the data agent(s) 142A, 142B may format the datainto a backup format or otherwise process the data suitable for a backupcopy.

At step 3, client computing device 102 communicates the processed filesystem data (e.g., using file system data agent 142A) and the processedemail data (e.g., using email data agent 142B) to the first media agent144A according to backup copy rule set 160, as directed by storagemanager 140. Storage manager 140 may further keep a record in managementdatabase 146 of the association between media agent 144A and one or moreof: client computing device 102, file system subclient 112A, file systemdata agent 142A, email subclient 112B, email data agent 142B, and/orbackup copy 116A.

The target media agent 144A receives the data-agent-processed data fromclient computing device 102, and at step 4 generates and conveys backupcopy 116A to disk library 108A to be stored as backup copy 116A, againat the direction of storage manager 140 and according to backup copyrule set 160. Media agent 144A can also update its index 153 to includedata and/or metadata related to backup copy 116A, such as informationindicating where the backup copy 116A resides on disk library 108A,where the email copy resides, where the file system copy resides, dataand metadata for cache retrieval, etc. Storage manager 140 may similarlyupdate its index 150 to include information relating to the secondarycopy operation, such as information relating to the type of operation, aphysical location associated with one or more copies created by theoperation, the time the operation was performed, status informationrelating to the operation, the components involved in the operation, andthe like. In some cases, storage manager 140 may update its index 150 toinclude some or all of the information stored in index 153 of mediaagent 144A. At this point, the backup job may be considered complete.After the 30-day retention period expires, storage manager 140 instructsmedia agent 144A to delete backup copy 116A from disk library 108A andindexes 150 and/or 153 are updated accordingly.

At step 5, storage manager 140 initiates another backup job for adisaster recovery copy according to the disaster recovery rule set 162.Illustratively this includes steps 5-7 occurring daily for creatingdisaster recovery copy 116B. Illustratively, and by way of illustratingthe scalable aspects and off-loading principles embedded in system 100,disaster recovery copy 116B is based on backup copy 116A and not onprimary data 112A and 112B.

At step 6, illustratively based on instructions received from storagemanager 140 at step 5, the specified media agent 144B retrieves the mostrecent backup copy 116A from disk library 108A.

At step 7, again at the direction of storage manager 140 and asspecified in disaster recovery copy rule set 162, media agent 144B usesthe retrieved data to create a disaster recovery copy 116B and store itto tape library 108B. In some cases, disaster recovery copy 116B is adirect, mirror copy of backup copy 116A, and remains in the backupformat. In other embodiments, disaster recovery copy 116B may be furthercompressed or encrypted, or may be generated in some other manner, suchas by using primary data 112A and 112B from primary storage device 104as sources. The disaster recovery copy operation is initiated once a dayand disaster recovery copies 116B are deleted after 60 days; indexes 153and/or 150 are updated accordingly when/after each informationmanagement operation is executed and/or completed. The present backupjob may be considered completed.

At step 8, storage manager 140 initiates another backup job according tocompliance rule set 164, which performs steps 8-9 quarterly to createcompliance copy 116C. For instance, storage manager 140 instructs mediaagent 144B to create compliance copy 116C on tape library 108B, asspecified in the compliance copy rule set 164.

At step 9 in the example, compliance copy 116C is generated usingdisaster recovery copy 116B as the source. This is efficient, becausedisaster recovery copy resides on the same secondary storage device andthus no network resources are required to move the data. In otherembodiments, compliance copy 116C is instead generated using primarydata 112B corresponding to the email subclient or using backup copy 116Afrom disk library 108A as source data. As specified in the illustratedexample, compliance copies 116C are created quarterly, and are deletedafter ten years, and indexes 153 and/or 150 are kept up-to-dateaccordingly.

Exemplary Applications of Storage Policies—Information GovernancePolicies and Classification

Again referring to FIG. 1E, storage manager 140 may permit a user tospecify aspects of storage policy 148A. For example, the storage policycan be modified to include information governance policies to define howdata should be managed in order to comply with a certain regulation orbusiness objective. The various policies may be stored, for example, inmanagement database 146. An information governance policy may align withone or more compliance tasks that are imposed by regulations or businessrequirements. Examples of information governance policies might includea Sarbanes-Oxley policy, a HIPAA policy, an electronic discovery(e-discovery) policy, and so on.

Information governance policies allow administrators to obtain differentperspectives on an organization's online and offline data, without theneed for a dedicated data silo created solely for each differentviewpoint. As described previously, the data storage systems hereinbuild an index that reflects the contents of a distributed data set thatspans numerous clients and storage devices, including both primary dataand secondary copies, and online and offline copies. An organization mayapply multiple information governance policies in a top-down manner overthat unified data set and indexing schema in order to view andmanipulate the data set through different lenses, each of which isadapted to a particular compliance or business goal. Thus, for example,by applying an e-discovery policy and a Sarbanes-Oxley policy, twodifferent groups of users in an organization can conduct two verydifferent analyses of the same underlying physical set of data/copies,which may be distributed throughout the information management system.

An information governance policy may comprise a classification policy,which defines a taxonomy of classification terms or tags relevant to acompliance task and/or business objective. A classification policy mayalso associate a defined tag with a classification rule. Aclassification rule defines a particular combination of criteria, suchas users who have created, accessed or modified a document or dataobject; file or application types; content or metadata keywords; clientsor storage locations; dates of data creation and/or access; reviewstatus or other status within a workflow (e.g., reviewed orun-reviewed); modification times or types of modifications; and/or anyother data attributes in any combination, without limitation. Aclassification rule may also be defined using other classification tagsin the taxonomy. The various criteria used to define a classificationrule may be combined in any suitable fashion, for example, via Booleanoperators, to define a complex classification rule. As an example, ane-discovery classification policy might define a classification tag“privileged” that is associated with documents or data objects that (1)were created or modified by legal department staff, or (2) were sent toor received from outside counsel via email, or (3) contain one of thefollowing keywords: “privileged” or “attorney” or “counsel,” or otherlike terms. Accordingly, all these documents or data objects will beclassified as “privileged.”

One specific type of classification tag, which may be added to an indexat the time of indexing, is an “entity tag.” An entity tag may be, forexample, any content that matches a defined data mask format. Examplesof entity tags might include, e.g., social security numbers (e.g., anynumerical content matching the formatting mask XXX-XX-XXXX), credit cardnumbers (e.g., content having a 13-16 digit string of numbers), SKUnumbers, product numbers, etc. A user may define a classification policyby indicating criteria, parameters or descriptors of the policy via agraphical user interface, such as a form or page with fields to befilled in, pull-down menus or entries allowing one or more of severaloptions to be selected, buttons, sliders, hypertext links or other knownuser interface tools for receiving user input, etc. For example, a usermay define certain entity tags, such as a particular product number orproject ID. In some implementations, the classification policy can beimplemented using cloud-based techniques. For example, the storagedevices may be cloud storage devices, and the storage manager 140 mayexecute cloud service provider API over a network to classify datastored on cloud storage devices.

Restore Operations from Secondary Copies

While not shown in FIG. 1E, at some later point in time, a restoreoperation can be initiated involving one or more of secondary copies116A, 116B, and 116C. A restore operation logically takes a selectedsecondary copy 116, reverses the effects of the secondary copy operationthat created it, and stores the restored data to primary storage where aclient computing device 102 may properly access it as primary data. Amedia agent 144 and an appropriate data agent 142 (e.g., executing onthe client computing device 102) perform the tasks needed to complete arestore operation. For example, data that was encrypted, compressed,and/or deduplicated in the creation of secondary copy 116 will becorrespondingly rehydrated (reversing deduplication), uncompressed, andunencrypted into a format appropriate to primary data. Metadata storedwithin or associated with the secondary copy 116 may be used during therestore operation. In general, restored data should be indistinguishablefrom other primary data 112. Preferably, the restored data has fullyregained the native format that may make it immediately usable byapplication 110.

As one example, a user may manually initiate a restore of backup copy116A, e.g., by interacting with user interface 158 of storage manager140 or with a web-based console with access to system 100. Storagemanager 140 may accesses data in its index 150 and/or managementdatabase 146 (and/or the respective storage policy 148A) associated withthe selected backup copy 116A to identify the appropriate media agent144A and/or secondary storage device 108A where the secondary copyresides. The user may be presented with a representation (e.g., stub,thumbnail, listing, etc.) and metadata about the selected secondarycopy, in order to determine whether this is the appropriate copy to berestored, e.g., date that the original primary data was created. Storagemanager 140 will then instruct media agent 144A and an appropriate dataagent 142 on the target client computing device 102 to restore secondarycopy 116A to primary storage device 104. A media agent may be selectedfor use in the restore operation based on a load balancing algorithm, anavailability based algorithm, or other criteria. The selected mediaagent, e.g., 144A, retrieves secondary copy 116A from disk library 108A.For instance, media agent 144A may access its index 153 to identify alocation of backup copy 116A on disk library 108A, or may accesslocation information residing on disk library 108A itself.

In some cases a backup copy 116A that was recently created or accessed,may be cached to speed up the restore operation. In such a case, mediaagent 144A accesses a cached version of backup copy 116A residing inindex 153, without having to access disk library 108A for some or all ofthe data. Once it has retrieved backup copy 116A, the media agent 144Acommunicates the data to the requesting client computing device 102.Upon receipt, file system data agent 142A and email data agent 142B mayunpack (e.g., restore from a backup format to the native applicationformat) the data in backup copy 116A and restore the unpackaged data toprimary storage device 104. In general, secondary copies 116 may berestored to the same volume or folder in primary storage device 104 fromwhich the secondary copy was derived; to another storage location orclient computing device 102; to shared storage, etc. In some cases, thedata may be restored so that it may be used by an application 110 of adifferent version/vintage from the application that created the originalprimary data 112.

Exemplary Secondary Copy Formatting

The formatting and structure of secondary copies 116 can vary dependingon the embodiment. In some cases, secondary copies 116 are formatted asa series of logical data units or “chunks” (e.g., 512 MB, 1 GB, 2 GB, 4GB, or 8 GB chunks). This can facilitate efficient communication andwriting to secondary storage devices 108, e.g., according to resourceavailability. For example, a single secondary copy 116 may be written ona chunk-by-chunk basis to one or more secondary storage devices 108. Insome cases, users can select different chunk sizes, e.g., to improvethroughput to tape storage devices. Generally, each chunk can include aheader and a payload. The payload can include files (or other dataunits) or subsets thereof included in the chunk, whereas the chunkheader generally includes metadata relating to the chunk, some or all ofwhich may be derived from the payload. For example, during a secondarycopy operation, media agent 144, storage manager 140, or other componentmay divide files into chunks and generate headers for each chunk byprocessing the files. Headers can include a variety of information suchas file and/or volume identifier(s), offset(s), and/or other informationassociated with the payload data items, a chunk sequence number, etc.Importantly, in addition to being stored with secondary copy 116 onsecondary storage device 108, chunk headers can also be stored to index153 of the associated media agent(s) 144 and/or to index 150 associatedwith storage manager 140. This can be useful for providing fasterprocessing of secondary copies 116 during browsing, restores, or otheroperations. In some cases, once a chunk is successfully transferred to asecondary storage device 108, the secondary storage device 108 returnsan indication of receipt, e.g., to media agent 144 and/or storagemanager 140, which may update their respective indexes 153, 150accordingly. During restore, chunks may be processed (e.g., by mediaagent 144) according to the information in the chunk header toreassemble the files.

Data can also be communicated within system 100 in data channels thatconnect client computing devices 102 to secondary storage devices 108.These data channels can be referred to as “data streams,” and multipledata streams can be employed to parallelize an information managementoperation, improving data transfer rate, among other advantages. Exampledata formatting techniques including techniques involving datastreaming, chunking, and the use of other data structures in creatingsecondary copies are described in U.S. Pat. Nos. 7,315,923, 8,156,086,and 8,578,120.

FIGS. 1F and 1G are diagrams of example data streams 170 and 171,respectively, which may be employed for performing informationmanagement operations. Referring to FIG. 1F, data agent 142 forms datastream 170 from source data associated with a client computing device102 (e.g., primary data 112). Data stream 170 is composed of multiplepairs of stream header 172 and stream data (or stream payload) 174. Datastreams 170 and 171 shown in the illustrated example are for asingle-instanced storage operation, and a stream payload 174 thereforemay include both single-instance (SI) data and/or non-SI data. A streamheader 172 includes metadata about the stream payload 174. This metadatamay include, for example, a length of the stream payload 174, anindication of whether the stream payload 174 is encrypted, an indicationof whether the stream payload 174 is compressed, an archive fileidentifier (ID), an indication of whether the stream payload 174 issingle instanceable, and an indication of whether the stream payload 174is a start of a block of data.

Referring to FIG. 1G, data stream 171 has the stream header 172 andstream payload 174 aligned into multiple data blocks. In this example,the data blocks are of size 64 KB. The first two stream header 172 andstream payload 174 pairs comprise a first data block of size 64 KB. Thefirst stream header 172 indicates that the length of the succeedingstream payload 174 is 63 KB and that it is the start of a data block.The next stream header 172 indicates that the succeeding stream payload174 has a length of 1 KB and that it is not the start of a new datablock. Immediately following stream payload 174 is a pair comprising anidentifier header 176 and identifier data 178. The identifier header 176includes an indication that the succeeding identifier data 178 includesthe identifier for the immediately previous data block. The identifierdata 178 includes the identifier that the data agent 142 generated forthe data block. The data stream 171 also includes other stream header172 and stream payload 174 pairs, which may be for SI data and/or non-SIdata.

FIG. 1H is a diagram illustrating data structures 180 that may be usedto store blocks of SI data and non-SI data on a storage device (e.g.,secondary storage device 108). According to certain embodiments, datastructures 180 do not form part of a native file system of the storagedevice. Data structures 180 include one or more volume folders 182, oneor more chunk folders 184/185 within the volume folder 182, and multiplefiles within chunk folder 184. Each chunk folder 184/185 includes ametadata file 186/187, a metadata index file 188/189, one or morecontainer files 190/191/193, and a container index file 192/194.Metadata file 186/187 stores non-SI data blocks as well as links to SIdata blocks stored in container files. Metadata index file 188/189stores an index to the data in the metadata file 186/187. Containerfiles 190/191/193 store SI data blocks. Container index file 192/194stores an index to container files 190/191/193. Among other things,container index file 192/194 stores an indication of whether acorresponding block in a container file 190/191/193 is referred to by alink in a metadata file 186/187. For example, data block B2 in thecontainer file 190 is referred to by a link in metadata file 187 inchunk folder 185. Accordingly, the corresponding index entry incontainer index file 192 indicates that data block B2 in container file190 is referred to. As another example, data block B1 in container file191 is referred to by a link in metadata file 187, and so thecorresponding index entry in container index file 192 indicates thatthis data block is referred to.

As an example, data structures 180 illustrated in FIG. 1H may have beencreated as a result of separate secondary copy operations involving twoclient computing devices 102. For example, a first secondary copyoperation on a first client computing device 102 could result in thecreation of the first chunk folder 184, and a second secondary copyoperation on a second client computing device 102 could result in thecreation of the second chunk folder 185. Container files 190/191 in thefirst chunk folder 184 would contain the blocks of SI data of the firstclient computing device 102. If the two client computing devices 102have substantially similar data, the second secondary copy operation onthe data of the second client computing device 102 would result in mediaagent 144 storing primarily links to the data blocks of the first clientcomputing device 102 that are already stored in the container files190/191. Accordingly, while a first secondary copy operation may resultin storing nearly all of the data subject to the operation, subsequentsecondary storage operations involving similar data may result insubstantial data storage space savings, because links to already storeddata blocks can be stored instead of additional instances of datablocks.

If the operating system of the secondary storage computing device 106 onwhich media agent 144 operates supports sparse files, then when mediaagent 144 creates container files 190/191/193, it can create them assparse files. A sparse file is a type of file that may include emptyspace (e.g., a sparse file may have real data within it, such as at thebeginning of the file and/or at the end of the file, but may also haveempty space in it that is not storing actual data, such as a contiguousrange of bytes all having a value of zero). Having container files190/191/193 be sparse files allows media agent 144 to free up space incontainer files 190/191/193 when blocks of data in container files190/191/193 no longer need to be stored on the storage devices. In someexamples, media agent 144 creates a new container file 190/191/193 whena container file 190/191/193 either includes 100 blocks of data or whenthe size of the container file 190 exceeds 50 MB. In other examples,media agent 144 creates a new container file 190/191/193 when acontainer file 190/191/193 satisfies other criteria (e.g., it containsfrom approx. 100 to approx. 1000 blocks or when its size exceedsapproximately 50 MB to 1 GB). In some cases, a file on which a secondarycopy operation is performed may comprise a large number of data blocks.For example, a 100 MB file may comprise 400 data blocks of size 256 KB.If such a file is to be stored, its data blocks may span more than onecontainer file, or even more than one chunk folder. As another example,a database file of 20 GB may comprise over 40,000 data blocks of size512 KB. If such a database file is to be stored, its data blocks willlikely span multiple container files, multiple chunk folders, andpotentially multiple volume folders. Restoring such files may requireaccessing multiple container files, chunk folders, and/or volume foldersto obtain the requisite data blocks.

Application-Level Live Synchronization Across Computing PlatformsIncluding Synchronizing Co-Resident Applications to Disparate StandbyDestinations and Selectively Synchronizing Some Applications and notOthers

FIG. 2 is a block diagram illustrating some salient portions of a system200 for application-level Live Synchronization across computingplatforms, according to an illustrative embodiment of the presentinvention. The illustrative system 200 employs delayed synchronizationas between an intermediary storage 108 that stores incremental backupsand the destination data storage 204 that comprises the standby diskimage of the targeted application. As shown here, application 110-1 andits associated file system 111-1 and associated primary data stored involume 1 and volume 2 are synchronized to standby/failover computingplatform 222, resulting in a so-called “synchronized application 110S-1”that acts as a standby for primary application 110-1. On a failure ofapplication 110-1 or its file system 111-1 or its associated primarydata storage 104, synchronized application 110S-1 can take over oncomputing platform 222. Synchronized application 110S-1 becomes theprimary until such time as control is restored to application 110-1. Theconfiguration shown in the present figure uses incremental block-levelbackups to an intermediary secondary storage device followed by restoreoperations to the standby/failover destination. This process can delayhow soon the standby/failover destination is updated. Therefore, analternative configuration shown in FIG. 3 uses block-level continuousdata replication to maintain a flow of changing blocks captured at thesource and replicated to the standby copy at the standby/failoverdestination.

Computing platform 202 hosts one or more applications 110 operating inthe production environment, which may be referred to as “primaryapplications 110.” Primary data for the primary applications 110 isstored in an associated primary data storage device 104. Computingplatform 202 may be a physical computing device (e.g., server, laptop,etc.) or may be embodied as a virtual machine or container operating ina virtualized production environment, whether it is a private cloud or apublic cloud. Computing platform 202 provides computing power that hostsprimary applications 110. In contrast to client computing device 102,computing platform 202 does not have installed data agents 142 paired tothe hosted applications and file system(s). Instead, according to thedisclosed architecture, enhanced data agent(s) 242 operate on a separateand distinct computing platform, e.g., 206, and comprise thefunctionality to protect primary applications 110 from there withoutco-residing with the target applications on computing platform 202.Because it hosts primary applications in the production environment,computing platform 202 may be referred to herein as a “primary host.”System 200 (and system 300) may comprise any number of primary hosts 202executing any number of primary applications 110.

Standby/failover computing platform 222 hosts one or more applications110S that are maintained in Live Synchronization with the primaryapplications 110 at computing platform 202. Computing platform 222 maybe a different type of computing platform than primary host 202, e.g.,physical or virtualized. Computing platform 222 may be a different kindof virtualized environment than primary host 202, e.g., a differentmanufacturer, different product, different version, etc. Computingplatform 222 may host a different number of applications 110S thanprimary host 202, and may also host a different set of applications 110Sthat are Live Synched from a plurality of primary hosts 202. Also, oneprimary application 110 may be Live Synched to more than onestandby/failover destination 222. System 200 (and system 300) maycomprise any number of standby/failover computing platforms 222supporting any number of synchronized applications 110S.

Enhanced storage manager 240 is analogous to storage manager 140 andfurther comprises functional enhancements for operating in theillustrative systems disclosed herein. Enhanced storage manager 240manages system 200 (and system 300) as well as managing storageoperations within the system. Enhanced storage manager 240 transmitsqueries and/or instructions to enhanced data agent 242 and to mediaagents 144/244 involved in the disclosed storage operations of theillustrative embodiments. In some embodiments, storage manager 240orchestrates (e.g., controls, instructs, and monitors) the performanceof the storage operations described here, such as: auto-discovery byenhanced data agent 242 relative to a set of primary applications 110;pushing application utilities (e.g., 570, 670) and/or changed blockfilters (e.g., 440, 540) to the primary hosts (e.g., 202); incrementalbackups and/or continuous data replication of the targeted primaryapplications 110; restore operations to the standby/failover platform,if applicable; detecting failure of primary applications 110 anddirecting synchronized application 110S to take over; etc., withoutlimitation. For example, storage manager 240 transmits queries to theenhanced data agent 242 asking about applications in the illustrativesystem. In response to receiving such a query, enhanced data agent 242begins the process of automatic discovery of the applications and theiroperational properties, such as type of application, file systemconfiguration, primary data configuration (e.g., storage volume IDs) anddisk image (e.g., VMDK-1 450). The enhanced storage manager 240 mayinstruct the enhanced data agent 242 to proceed with further discoveryof whether connectors/APIs and/or changed block trackers are nativelyavailable in the discovered applications. In some alternativeembodiments, the enhanced data agent 242 performs these discovery stepsautonomously without explicit instruction from storage manager 240.Storage manager 240 may further provide scheduling information toenhanced data agent 242, e.g., how often to execute incremental backupsand how often to synchronize the backups to the standby destination.Storage manager 240 may also instruct when to perform a baseline fullbackup of the targeted primary application 110.

Enhanced data agent 242 is analogous to data agent 142 and furthercomprises functional enhancements for operating in the illustrativesystems disclosed herein. Enhanced data agent 242 is largely responsiblefor performing and/or causing to perform the majority of thefunctionality disclosed herein. See, e.g., method 700. Illustrativefeatures of enhanced data agent 242 include one or more of the followingwithout limitation: identifying applications 110 on host computingplatforms; determining whether the identified applications are targetedfor Live Sync (e.g., based on instructions from storage manager, basedon type of application, based on host, etc.); determining whethertargeted applications comprise connectors/APIs for communicating withthe enhanced data agent, and if not, installing such functionality(application utilities); auto discovering the targeted applications'operational characteristics, including identifying and locating the diskimage that represents each targeted application; determining whether thetargeted utilities are capable of self-tracking changed data blocks fromwrite operations, and if not, installing such functionality(application-specific block change filter); managing ongoingsynchronization based on the changed blocks, by applying block changesto the standby copy of the disk image that represents the respectiveapplication—thus keeping the standby copy of the disk image synchronizedwith the primary disk image; detecting a failure of the primaryapplication 110 and causing the synchronized application 110S to boot upfrom the standby copy of the disk image to begin operating in place ofthe primary application 110. Enhanced data agent 242 also supportsreverse synchronization whereby an active standby application is reversesynchronized back to a proper primary platform, e.g., after recoveryfrom a disaster when a primary platform is operational and ready. Moredetails are given in subsequent figures.

Enhanced data agent 242 may be any type of block-level data agent, e.g.,a virtual server data agent type when associated with computing platform202 that is a virtual server. The enhanced functionality of data agent242 disclosed herein is implemented irrespective of the type of dataagent.

System 200 (and system 300) may comprise any number of secondary storagecomputing devices 206 and enhanced data agents 242, sufficient to enablethe application-specific Live Synchronization functionality disclosedherein. In addition, traditional pairs of application/file system anddata agent 142 also may be configured in the disclosed system forapplications that are not targeted for Live Synchronization.

Logical pathways 1, 2, and 3 represent logical pathways forinter-component communications and/or data flows and are depicted bybold dotted arrows. These logical pathways (as well as others like themdepicted in other figures herein) depict certain communication aspectsof the illustrative systems, and are not a reflection of or limited tocertain communications infrastructure, nor do they necessarily depictdirect communications between the respective components, nor do theynecessarily include every component needed to support the depictedlogical pathway. Any physical communications infrastructure known in theart may be implemented to carry the inter-component communications anddata flows described herein.

Logical pathway 1 between enhanced data agent 242 and computing platform202, which hosts the primary applications, is used generally forauto-discovery of the applications, pushing application utility 570/670,pushing changed block filter 440/540, quiescing and un-quiescing thetargeted application, and instructing certain targeted applications toperform self-backups, e.g., full and/or incremental backups.

Logical pathway 2 captures data blocks from the primary application andstores them to an intermediary secondary storage device 108. These datablocks may take the form of an initial baseline full backup of thetargeted application's disk image followed by subsequent incrementalbackups. A media agent 144 (not shown) is generally associated with andacts as a storage portal to secondary storage device 108.

Logical pathway 3 is used for transmitting data blocks from theintermediary secondary storage device 108 to the destination datastorage device 204. This takes the form of a restore operation of thebacked up data blocks to a standby copy of the disk image of thetargeted application. Because the restore operation follows and may beasynchronous with the backups to the intermediary storage, it isreferred to as “delayed synchronization.” The delayed synchronizationupdates the standby copy of the disk image (e.g., 460), enabling thestandby application to become synchronized to the primary. The standbyimage (e.g., 460) is then used as the boot image when the synchronizedapplication 110S must take over from the primary 110, e.g., when theprimary application fails.

Notably, some components are not explicitly depicted in the presentfigure (or in other figures herein), e.g., a media agent 144 used forstoring backups to secondary storage device 108. Likewise, certaincommunication pathways and signaling connections also are not depicted,e.g., a media agent 144 used for restoring the backup copies to thestandby destination may be the one depicted in the present figure or maybe another media agent designated for the restore tasks. Some furtherdetails are depicted and/or described in subsequent figures.

FIG. 3 is a block diagram illustrating some salient portions of a system300 for application-level Live Synchronization using block-levelcontinuous data replication, according to another illustrativeembodiment of the present invention. The illustrative system 300 employsblock-level (as contrasted to file-level) continuous data replication(“CDR”) as between the primary data application and the standby diskimage of the targeted application stored in the destination data storage204. As shown here, application 110-1 and its associated file system111-1 and associated primary data stored in volume 1 and volume 2 areLive Synched using block-level CDR to standby/failover computingplatform 222, resulting in a so-called “synchronized application 110S-1”that is a standby for primary application 110-1. On a failure ofapplication 110-1 or its file system 111-1 or its associated primarydata storage 104, synchronized application 110S-1 can take over oncomputing platform 222. Synchronized application 110S-1 becomes theprimary until such time as control is restored to application 110-1.Logical pathways 1 and 4 represent logical pathways for inter-componentcommunications and/or data flows and are depicted by bold dotted arrows.These logical pathways depict certain communication aspects of theillustrative systems, and are not a reflection of or limited to certaincommunications infrastructure, nor do they necessarily depict directcommunications, nor do they necessarily include every component neededto support the logical pathway. Any physical communicationsinfrastructure known in the art may be implemented to carry theinter-component communications described herein. The system can utilizethe deduplicated copy techniques described in U.S. Pat. No. 9,239,687,entitled “Systems and Methods for Retaining and Using Data BlockSignatures in Data Protection Operations” and in U.S. patent applicationSer. No. 14/721,971, entitled “Replication Using Deduplicated SecondaryCopy Data.”

Logical pathway 1 is analogous to logical pathway 1 in FIG. 2.

Logical pathway 4 is used for capturing changed data blocks from thetargeted primary application and on a continuing basis transporting themto update the standby disk image at the standby/failover destination. Asshown here, application 110-1 and its associated file system 111-1 andassociated primary data stored in volume 1 and volume 2 are LiveSynchronized to standby/failover computing platform 222 usingblock-level CDR, resulting in a so-called “synchronized application110S-1” that is a standby for primary application 110-1. Synchronizedapplication 110S-1 becomes the primary until such time as control isrestored to application 110-1. In contrast to FIG. 2, the system of FIG.3 uses block-level continuous data replication (“CDR”) to update thestandby copy of the disk image and there is no intermediate storage andno delayed synchronization. As a result, block-level continuous datareplication is a preferred embodiment for keeping the standby copy ofthe disk image as closely synchronized in time with the primaryapplication 110.

Even though system 200 and system 300 are illustrated in separatefigures, the invention is not so limited. A given system according tothe present invention may perform Live Synchronization via incrementalbackups and delayed sync for some targeted application(s) (as shown insystem 200) while also performing Live Synchronization via block-levelcontinuous data replication for other targeted application(s) (as shownin system 300) and may furthermore NOT keep certain other applicationsLive Synched at all (as shown in FIG. 10). The choice of one approachover the other depends on bandwidth, processing capacity at the primaryhost, and/or concerns over whether and how closely the standby systemshould be kept synchronized to the primary.

FIG. 4A is a block diagram illustrating some details of system 300,including logical communication pathways between certain components forLive Synchronization of an illustrative application 110-1 usingblock-level continuous data replication from primary disk image to astandby copy in native application format. FIG. 4A depicts: computingplatform 202 hosting primary application 110-1 (e.g., Oracle DBMS),which comprises a native connector/API 430, also hosting file system111-1 (e.g., Oracle FS), and further hosting an installedapplication-specific block change filter 440; enhanced data agent 242comprising discover and quiesce module 410, which comprises app-specificconnectors 411 and 412, and further comprising a secondary copycontroller 420; application-specific disk image 450 (e.g., VMDK-1comprising volume 1 and volume 2); and synchronized application 110S,comprising application 110S-1 and file system 111S-1 hosted by computingplatform 222 and standby copy 460 of the application-specific disk imagestored in storage device 204. The present figure depicts a number ofinter-component logical pathways described in further detail below.

Primary application 110-1 is any executable application that is hostedby a computing platform such as 202 (e.g., virtual machine, physicalserver, container, etc.). Application 110-1 is targeted for LiveSynchronization according to the illustrative embodiment. Illustrativetypes of applications that might be targeted for Live Synch includeOracle database management systems (DBMS) from Oracle Corp.; SQLdatabase management systems from Microsoft Corp.; etc.

File system 111-1 is any file system that is associated with theapplication 110-1, i.e., wherein the file system 111 controls,organizes, and maintains the structure and logic (e.g., directories,hierarchies) of data used by application 110 and controls how theapplication 110 accesses mass storage including how data is storedthereto and retrieved therefrom. As illustrated in the present figure,file system 111-1 controls storage volume 1 and storage volume 2 inprimary storage device 104, which collectively store the disk image forapplication 110-1 (e.g., VMDK-1).

The term “synchronized application 110S-1” (component 223) is usedherein as shorthand to refer to application 110S-1 and file system111S-1, which are hosted by computing platform 222 coupled with astandby copy 460 of the application-specific disk image that is storedin storage device 204. Although computing platform 222, which hosts thestandby synchronized application, may be different from computingplatform 202 which hosts the primary application, the respectiveapplications, i.e., 110-1 and 110S-1, are the same; likewise thecorresponding file systems 111-1 and 111S-1 are sufficiently alike toenable application 110S-1 to boot up from standby copy 460 of the diskimage and to access/manage data therefrom via file system 111S-1. Thestandby copy 460 of the disk image is in application-native format andkept up to date according to the illustrative embodiments (e.g., usingblock-level continuous data replication) so that application 110S-1 mayboot up from the standby image and operate successfully as needed;accordingly, standby copy 460 may but need not comprise a data volume 1and a data volume 2 (not shown) that correspond to the primary datavolumes 1 and 2 in storage device 104. As noted elsewhere herein, insome embodiments, only one of volumes 1 and 2 may be synchronized to thestandby/failover destination and not the other volume.

Discover and quiesce module 410 is a sub-component of enhanced dataagent 242. Discover and quiesce module 410 is generally responsible forestablishing communications with computing platforms such as 202 thathost applications in system 200/300, and then using anapplication-specific connector (e.g., 411, 412) to communicate withrespective applications 110, discover their configurations andoperational characteristics, quiesce them prior to a secondary copyoperation, and un-quiesce them after the secondary copy is taken.Discover and quiesce module 410 may comprise any number ofapplication-specific connectors such as 411 and 412 and/or otherconnectors such as API-specific connectors that can use a given API tocommunicate with any number of applications 110 supporting that API.Discover and quiesce module 410 also may “push” to computing platform202 an application utility 570 (see FIG. 5) which is to couple to thetargeted application 110 hosted by computing platform 202.

Application-specific connectors 411 and 412 are sub-components ofenhanced data agent 242. Each application-specific connector 411/412comprises logic that is capable of communicating with a particular typeof application 110, or more particularly, communicating with certainlogic associated with the application that allows the connector 411/412to discover the application's configuration and operationalcharacteristics, including type of application, version, file system,storage configuration, nomenclature, etc.; instruct the application 110to quiesce; and instruct the application 110 to un-quiesce. Theapplication-specific connector 411/412 may communicate with certainnative features in the application 110, such as a native connector orapplication programming interface (“API”) 430; in some cases, anapplication 110 that lacks such a native feature will be coupled with aninstalled application utility 570 (see FIG. 5) that is pushed thereto bythe enhanced data agent 242 (e.g., using discover and quiesce module410).

Secondary copy controller 420 is a sub-component of enhanced data agent242, which is responsible for determining whether a targeted application110 comprises a native feature for tracking changed data blocks (e.g.,680), and if not, pushing such a utility thereto (e.g., 440, 540);instructing a changed block utility (whether native or installed) totransmit changed data blocks to data agent 242; receiving changed datablocks from the changed block utility (e.g., 440, 540, 680); andcontinuously transmitting them to the standby disk image 460 forcontinuous update (or, in come embodiments where enhanced data agent 242lacks control over storage device 204, transmitting the changed datablocks to another data agent 242 that resides on destination platform222 and which in turn will update the standby disk image 460). Secondarycopy controller 420 also may generate full backups ofapplication-specific disk image 450 as a baseline operation beforeapplication-specific incremental backups and/or CDR begins for theapplication. Thus, secondary copy controller 420 comprises logic forsupporting application-specific Live Synchronization operations relativeto certain targeted applications.

Native connector/API 430 is a feature of primary application 110. Thisfeature is generally provided by the application's manufacturer/vendorso that external entities may communicate and interact with theapplication. In some cases, the native connector/API is a publishedstandard that is used by multiple vendors; in other cases, the nativeconnector/API is proprietary to the application's manufacturer/vendor,but is published by the vendor to enable communications andinteractions.

Installed application-specific block change filter 440 (“CVBF”) is autility that is part of the illustrative embodiment and is supplied byand pushed to computing platform 202 by enhanced data agent 242 (e.g.,using secondary copy controller 420); it is not native to theapplication 110-1 and file system 111-1 being tracked. Filter 440 mayoperate in the operating system of the host computing platform 202.Filter 440 monitors write operations performed by primary application110-1 and keeps track of changes to data blocks resulting from thesewrite operations. Though the changed data blocks as written byapplication 110-1 reside in the application's disk image 450 (e.g., involume 1 or volume 2), filter 440 tracks the changes relative to abaseline full backup and then relative to subsequent changes. As aresult, filter 440 transmits changed data blocks on an ongoing basis forblock-level continuous data replication. In some embodiments, thechanged blocks are accumulated at an intermediate storage as shown inFIG. 2. In some other embodiments, the changed data blocks are saved bya media agent as application-consistent point-in-time recoverypoints—apart from being continuously replicated to the standby copy ofthe disk image—as shown in FIG. 4C.

Application-specific disk image 450 (e.g., VMDK-1 comprising volume 1and volume 2) comprises all primary data including metadata (e.g.,application state, configuration, etc.) associated with application110-1 and its file system 111-1. If we want to have a synchronizedstandby application 110S-1, disk image 450 is the collective datastructure to be copied to and maintained current at the standby/failoverdestination storage 204. A copy of disk image 450 is maintained asstandby copy 460 (in application-native format) from which application110S-1 can boot up to take over from the primary application 110-1.

Logical pathways 5, 6, and 6A represent logical pathways forinter-component communications and/or data flows and are depicted bybold dotted arrows. These logical pathways depict certain communicationaspects and are not a reflection of or limited to certain communicationsinfrastructure, nor do they necessarily depict direct communications,nor do they necessarily include every component needed to support thedepicted logical pathway. Any physical communications infrastructureknown in the art may be implemented to carry the inter-componentcommunications described herein.

Logical pathway 5 depicts the interactions, including control messagesand responses, between application-specific connector 411 and its targetapplication 110-1 using native connector/API 430, e.g., used forauto-discovery, quiescing and un-quiescing application 110-1.

Logical pathway 6 depicts the interactions between secondary copycontroller 420 and installed application-specific block change filter440 (pushed thereto by e.g., controller 420). Interactions includepushing filter 440 to computing platform 202 for purposes of tracking atargeted application's changed blocks; installing block filter 440thereon, associating it with application 110-1/file system 111-1/diskimage 450, and activating filter 440; and transmittingapplication-specific changed blocks from filter 440 to controller 420 onan ongoing basis to support block-level continuous data replication.

Logical pathway 6A depicts the transmission of application-specificchanged data blocks from controller 420 to standby copy 460. Inconfigurations where enhanced data agent 242 has control over storagedevice 204 which houses standby copy 460, controller 420 continuouslytransmits the changed data blocks received from filter 440 to standbycopy 460, thereby keeping standby copy 460 up-to-date with changing datablocks. In configurations where enhanced data agent 242 lacks controlover storage device 204 which houses standby copy 460, an intermediarydata agent 242 (not shown) is installed on the standby/failovercomputing platform (e.g., 222) and receives the changed data blockstransmitted by controller 420 and in turn updates standby copy 460 on anongoing basis. Thus, continuous data replication may occur directly fromenhanced data agent 242 or indirectly via a destination-based data agent(not shown).

FIG. 4B is a block diagram illustrating some details of system 300,including logical communication pathways between certain components forLive Synchronization of an illustrative application 110-1 usingcontinuous data replication from primary disk image to a standby copyand further depicting the generating of consistent (point-in-time)recovery points via snapshots taken at the standby/failover destination.FIG. 4B depicts some of the same components as FIG. 4A and additionallydepicts recovery point 461 stored in storage device 204 at thestandby/failover destination. Certain operational components, e.g.,standby/failover computing platform 222, are not depicted in the presentfigure due to lack of space.

Logical pathways 5, 6, and 6A were described in the preceding figure.

Logical pathway 6B depicts how a snapshot 461 of standby copy 460 istaken and stored at the standby/failover destination; the snapshot 461is to be used as an application-consistent point-in-time recovery pointin case it is needed for standby application 110S (or possibly primaryapplication 110) to revert to good known past point in time.Accordingly, when enhanced data agent 242 (e.g., secondary copycontroller 420) becomes aware that primary application 110 is in a “goodstate,” (e.g., because it has been quiesced or passed a maintenanceroutine, etc.), enhanced data agent 242 not only transmits changed datablocks to the standby/failover destination using logical pathway 6A, butadditionally sends control messages or instructions to the destinationstorage device (e.g., 204) to take a hardware snapshot of the updatedstandby copy 460 and store the hardware snapshot as a separateidentifiable data structure 461. Thus, snapshot 461 becomes a known goodcopy that can act as a recovery point for the synchronized application.Alternatively, instead of communicating with the destination storagedevice, enhanced data agent 242 may instruct the standby/failovercomputing platform (e.g., 222) to take a software snapshot of thestandby copy 460 and store it as a separately identifiable datastructure 461. Because it is a snapshot of standby copy 460, which is inapplication-native format, snapshot 461 is also in the sameapplication-native format and can also be used to rapidly boot upapplication 110S therefrom.

FIG. 4C is a block diagram illustrating some details of system 300,including the use of a media agent to save application-consistent(point-in-time) recovery points to secondary storage when usingblock-level continuous data replication to Live Sync an application110-1. FIG. 4C depicts some of the same components as FIG. 4A andadditionally depicts a media agent 244 that saves application-consistent(point-in-time) recovery points based on changed data blocks fromenhanced data agent 242 and saves the recovery point copies 462 to anassociated secondary storage device 404. As in FIG. 4B, when enhanceddata agent 242 (e.g., secondary copy controller 420) becomes aware thatprimary application 110 is in a “good state,” (e.g., because it has beenquiesced or passed a maintenance routine, etc.), enhanced data agent 242not only transmits changed data blocks to the standby/failoverdestination using logical pathway 6A, but additionally sends controlmessages or instructions to media agent 244 informing it of a “goodstate.”

Media agent 244 is similar to media agent 144 and acts as a portal tothe associated storage device 404. Additionally, media agent 244comprises intelligent logic for receiving and tracking changed datablocks received from enhanced data agent 242 and maintainingpoint-in-time copies 462 as recovery points of known good stated, e.g.,every 15 minutes, which could be used for a restore operation in case anolder good point in time were required. Media agent 244 furthercomprises logic for consolidating multiple recovery points periodicallyto a consolidated current version, e.g., consolidating quarter-hourcopies 462 into an hourly copy and consolidating hourly copies into oneend-of-day copy on a daily basis. The copies 462 may be restored to anycomputing platform in system 300 (or 200) as needed using restoreoperations that are well known in the art.

Logical pathways 5, 6, and 6A were described in preceding figures.

Logical pathway 7 depicts how changed data blocks are transmitted byenhanced data agent 242 to media agent 244, and logical pathway 7Adepicts how media agent 244 writes the changed data blocks to copies462.

FIG. 5 is a block diagram illustrating some details of system 300,including logical pathways between certain components for LiveSynchronization of an illustrative application 110-2. FIG. 5 depicts:computing platform 202 hosting primary application 110-2 (e.g., MySQLDBMS), which lacks a native connector/API and is coupled to an installedapplication utility 570, also hosting file system 111-2 (e.g., MySQLFS), and further hosting an installed application-specific block changefilter 540; enhanced data agent 242 comprising discover and quiescemodule 410, which comprises app-specific connectors 411 and 412, andfurther comprising a secondary copy controller 420; application-specificdisk image 550 (e.g., VMDK-2 comprising volume 3); and synchronizedapplication 110S-2 (component 523), comprising application 110S-2 andfile system 111S-2 and standby copy of the application-specific diskimage 560 stored in storage device 504. The present figure depicts anumber of inter-component logical pathways as described in furtherdetail below.

Connector 412, is similar to connector 411, but is application-specificfor communicating with application 110-2, e.g., MySQL.

Synchronized application 110S-2 (component 523) represents the standbyinstantiation of primary application 110-2. Synchronized application110S-2 need not use the same computing platform and mass data storage assynchronized application 110S-1 (component 223), even though the sourceprimary applications and their primary data were co-resident oncomputing platform 202 and storage device 104, respectively. Here,standby copy 560 of the disk image VMDK2 is stored on a differentstorage device 504 and the standby application 110S-2 and its associatedfile system 111S-2 are hosted by a different computing platform 522,which is distinct from 222 hosting 110S-1/111S-1.

Installed application-specific block change filter 540 is analogous tofilter 440, but operates relative to application 110-2 and itsassociated file system 111-2 and primary data stored in disk image 550.

Installed application utility 570 (which may be embodied as a plug-in tothe targeted application) is installed and operates on computingplatform 202 and is pushed thereto by enhanced data agent 242 (e.g.,using discover and quiesce module 410) upon determining that thetargeted application 110-2 lacks a native connector/API feature.Installed application utility 570 comprises logic (includingapplication-specific logic) for coupling to application 110-2 andcomprises further logic for communicating with connector 412 to receiveand respond to control messages therefrom. For example, utility 570comprises logic for discovering operational characteristics ofapplication 110-2 and reporting the discovered information to connector412 at enhanced data agent 242; and quiescing and un-quiescingapplication 110-2 in response to control message received from connector412.

Logical pathways 9, 10, and 6A represent logical pathways forinter-component communications and/or data flows and are depicted bybold dotted arrows. These logical pathways depict certain communicationaspects of the illustrative systems, and are not a reflection of orlimited to certain communications infrastructure, nor do theynecessarily depict direct communications, nor do they necessarilyinclude every component needed to support the depicted logical pathway.Any physical communications infrastructure known in the art may beimplemented to carry the inter-component communications describedherein.

Logical pathway 6A was described in an earlier figure.

Logical pathway 9 depicts the interactions, including control messagesand responses, between application-specific connector 412 and its targetapplication 110-2 using installed application utility 570, e.g., usedfor auto-discover, quiescing and un-quiescing application 110-2.

Logical pathway 10 depicts the interactions between secondary copycontroller 420 and installed application-specific block change filter540 (pushed thereto by e.g., controller 420). Interactions includepushing filter 540 to computing platform 202 for purposes of tracking atargeted application's changed blocks; installing block filter 540thereon, associating it with application 110-2/file system 111-2, anddisk image 550, and activating filter 540; and transmittingapplication-specific changed blocks to controller 420.

FIG. 6 is a block diagram illustrating some details of system 300,including logical pathways between certain components for LiveSynchronization of an illustrative application 110-n that executes oncomputing platform 202. FIG. 6 depicts: computing platform 202 hostingprimary application 110-n, which lacks a native connector/API and iscoupled to an installed application utility 670, and also hosting filesystem 111-n, which comprises a native block tracker 680; enhanced dataagent 242 comprising discover and quiesce module 410, which comprisesapp-specific connectors 411 and 611, and further comprising a secondarycopy controller 620; application-specific disk image 650 (e.g., VMDK-ncomprising volume m); and synchronized application 110S-n (component623), comprising application 110S-n and file system 111S-n hosted bycomputing platform 622 and a standby copy 660 of theapplication-specific disk image stored in storage device 604. Thepresent figure depicts a number of inter-component logical pathwaysdescribed in further detail below.

Connector 611 is application specific and in communication withinstalled application utility 670, similar to connector 412 and utility570, respectively, described in FIG. 5. Application utility 670 may beembodied as a plug-in to primary application 110-n.

Secondary copy controller 620 is analogous to controller 420 describedin an earlier figure, but communicates with a native block tracker 680that is a feature of file system 111-n and/or of its associatedapplication 110-n. As a result, controller 620 comprises the logic andmessage set required to communicate with the native block tracker 680 toperform some of the operation described for controller 420. For example,controller 620 has logic that knows how tracker 680 operates, such aswhat data structures it generates and maintains to keep track of blockchanges written by application 110-n (e.g., a log, a journal, etc.), andfurther knows the message set required for communicating with tracker680. Consequently, controller 620 may request a copy of a changed blocklog or journal maintained by native tracker 680 and comprises logic forparsing the received log or journal to determine which data blocks havechanged and when and for processing them further for purposes ofgenerating incremental backups or CDR.

Disk image 650 is analogous to disk image 550 and comprises primary datafor application 110-n and its associated file system 111-n, stored involume “m.”

Native block tracker 680 is a feature of application 100-n or itsassociated file system 111-n. Native block tracker 680 may generatetracking data structures such as transaction logs or journals thatreflect what data blocks changes as a result of write operationsperformed by application 110-n.

Logical pathways 11, 12, and 6A represent logical pathways forinter-component communications and/or data flows and are depicted bybold dotted arrows. These logical pathways depict certain communicationaspects of the illustrative systems, and are not a reflection of orlimited to certain communications infrastructure, nor do theynecessarily depict direct communications, nor do they necessarilyinclude every component needed to support the depicted logical pathway.Any physical communications infrastructure known in the art may beimplemented to carry the inter-component communications describedherein.

Logical pathway 6A was described in an earlier figure.

Logical pathway 11 depicts the interactions, including control messagesand responses, between application-specific connector 611 and its targetapplication 110-n using installed application utility 670, e.g., usedfor auto-discovery, quiescing and un-quiescing application 110-n.

Logical pathway 12 depicts the interactions between secondary copycontroller 620 and native block tracker 680 associated with application110-n and file system 111-n. Interactions include sending controlmessages to tracker 680 (e.g., requesting logs/journals, etc. and/orinstructing that an incremental backup be taken) and transmittingapplication-specific changed blocks to controller 620.

FIG. 7 depicts some salient operations of a method 700 according to anillustrative embodiment of the present invention. In general, method 700may operate in system 200 or 300 or in a hybrid system 200/300 thatincludes both delayed sync and block-level continuous data replication.In general, method 700 may be performed by enhanced data agent 242 inconjunction with storage manager 240, as well as connectors/APIs andblock filters operating on the host computing platform, as described infurther detail below. In some circumstances, media agents, e.g., 144 and244, also perform some operations.

At block 702, enhanced data agent (“EDA”) 242 receives query(ies) fromstorage manager 240 asking about applications 110 installed in thestorage management system 200 or 300. Alternatively, storage manager 240instructs enhanced data agent 242 to auto-discover applications 110installed on one or more computing platforms that are in communicationwith the enhanced data agent. The queries and/or instructions maycomprise configuration or topology information to enable EDA 242 toperform the auto-discovery.

At block 704, enhanced data agent 242 auto-discovers applications 110,including respective associated file systems 111 and primary storage104, and identifies each application-specific disk image (e.g., 450,550, 650) residing in primary storage. The application-specific diskimage may take different forms depending on the computing platform,e.g., a virtualized environment uses VMDK disk images. More details aregiven in a subsequent figure.

At block 706, for each application 110 targeted to be Live Synchronized,a destination standby/failover computing platform (e.g., 222, 522, 622,1022, etc.) is chosen, which is independent of other co-residentapplications' respective destinations. First, it should be noted thatall applications 110 need NOT be targeted for Live Synchronization.Second, the choice of destination for any given targeted application ismade by storage manager 240, e.g., via input from a systemadministrator, and communicated to enhanced data agent 242. In somealternative embodiments, enhanced data agent 242 automatically choosesthe standby/failover destination of each targeted application based onknowledge about the network and available destinations available to theenhanced data agent 242.

One additional aspect is to provide options for administrators to evenmore closely tailor Live Synchronization to their needs. For example, asystem administrator may select only certain source data to besynchronized relative to a certain targeted application. Filteringcriteria include logical volume, hard disk, and/or folders/files. Thisapproach improves system performance by reducing the storage footprintof backups and of the standby copy, reduces network bandwidth, and saveson processing cycles required of the various components.

At block 708, for each application 110 targeted to be Live Synchronized,enhanced data agent 242 finds a suitable connector for the applicationand uses it (e.g., 411, 412, 611) to reach out to and quiesce theapplication 110.

At block 710, enhanced data agent 242 performs a full backup of theapplication's disk image (e.g., 450/VMDK-1) and restores the full backupto a standby copy of the disk image (e.g., to VMDK-1 standby copy 460)(a media agent 144 is involved for storing the backup). After therestore, the disk image copy is in application-native format. At thispoint, standby application 110S may be booted up from the disk imagecopy, e.g., 460. In some cases, the full backup is performed undercommand and control of storage manager 240 using proprietary messagingof components of the storage management system 200/300. In some cases,where the targeted application 110 has a self-backup feature, the fullbackup is performed by instructing the application 110 to generate afull backup of its disk image and transmit it to enhanced data agent242.

At block 712, following the baseline full backup, changed data blocksgenerated by each targeted application 110 are tracked on an ongoingbasis going forward. If the targeted application is synchronized usingincremental backups (see, e.g., FIG. 2), control passes to block 714. Ifthe targeted application is synchronized using block-level continuousdata replication (see, e.g., FIG. 3), control passes to block 716.

At block 714, enhanced data agent 242 takes incremental backups,consolidates the block changes if appropriate, and restores from anintermediate secondary storage to the disk image standby copy (e.g.,460, etc.) at the standby destination. More details are given in asubsequent figure.

At block 716, enhanced data agent 242 performs block-level continuousdata replication that mirrors changed data blocks in the application'sdisk image to the standby copy (e.g., 460) at the destination. Thestandby copy is updated continuously without having to restore frombackup. As noted earlier, according to the illustrative embodiments,synchronization is application-specific, and therefore blocks 714 and716 can co-exist in one system relative to different applications 110therein. More details are given in a subsequent figure.

At block 718, synchronized application 110S (e.g., 223, 523, 623, etc.)is available at this point on the standby/failover computing platform(e.g., 222, 522, 622, respectively) to take over from primaryapplication 110 based on the respective standby copy of the disk image(e.g., 460, 560, 660, respectively).

At block 720, a synchronized application 110S at the standby/failovercomputing platform is booted up from the corresponding copy of the diskimage, which is in a ready state from the preceding block. A failure ofthe primary application 110 may be detected by the storage managerand/or by the enhanced data agent 242 and/or by the components with theapplication 110, e.g., 430, 440, 570, 540, 670, 680. Upon detectingand/or receiving a report of the failure, the storage manager 240instructs enhanced data agent 242 to disable application 110 and to bootup the standby application 110S from the copy of the disk image (e.g.,460, 560, 660). Additional scenarios for performing the present blockare described elsewhere herein, e.g., test scenarios.

Advantages.

By booting from a copy of the disk image that is in application-nativeformat, Live Sync keeps the switchover time from primary to standby to aminimum after a failure is detected in the primary. As compared to thetraditional approach, the present approach takes substantially lesstime, because the traditional approach requires: (a) finding a backupcopy of the failed application within the storage management system andexecuting one or more restore operations (e.g., restore full backup andthen restore each incremental backup in turn) to bring the restoredoperation up to date, or (b) finding a backup copy of the entire diskcomprising all primary data from the associated computing platform(e.g., storage device 104 comprising volumes 1, 2, 3, . . . , m),restoring the entire disk, and then identifying the target applicationand booting it up. Instead, the Live Synchronization approach disclosedherein specifically targets certain important applications for LiveSync, and maintains each targeted application in a “warm” state at thestandby/failover destination by extracting only application-specificdisk images from the source storage device 104 (e.g., only VMDK-1) andensuring that block changes thereto are regularly pushed to thedestination (e.g., using block-level CDR) so that the standby canquickly boot up from the standby disk image copy (e.g., 460, 560, 660).Importantly, the illustrative systems can support cross-platform LiveSynchronization, such that the source/host and destination/standbycomputing platforms can be of different types and technologies, e.g.,from physical server to virtual machine and vice-versa, from one type ofvirtualized environment to another, from one type of container toanother, etc. Moreover, co-resident applications can be separated asneeded independently of each other, such that co-resident primaryapplications can be dispersed to different and distinct standby/failoverdestinations (see FIG. 10), and vice-versa, previously separated primaryapplications can be Live Synchronized to the same standby/failoverdestination.

Block-level continuous data replication from primary to standby diskimage without using intermediary backups and restores provides anotherimportant advantage, because it enables the illustrative system to keepthe standby copy closely mirroring changes in the primary, so thatlittle or no data is lost when a switchover from primary to standby isneeded. The result is that a given application may be kept in a ready“warm” state at one or more standby/failover destinations, quiteindependent of how the application's co-resident applications and/orprimary storage is treated in case of a failure in the primaryproduction environment.

Another key take-away is that using the new architecture disclosedherein, one enhanced data agent 242 can support a number of distinctprimary applications 110 on one or more computing platforms, e.g., 202.This solution greatly reduces the footprint and installation/managementeffort associated with more traditional data agents, which areindividually paired with a target application and separately with itsfile system. Instead, according to the illustrative embodiments, asubstantial number of primary applications 110 can be protected by oneenhanced data agent 242 and by limited-footprint components (if any) onthe primary computing platform, such as installed application utilities570, 670 and/or installed application-specific block change filters 440,540. In many systems enhanced data agent 242 may co-reside with a mediaagent 144/244 on a secondary storage computing device 206, which meansthat the enhanced data agent 242 does not require additional specializedcomputing hardware.

FIG. 8A depicts some salient sub-operations of block 704 in method 700.Block 704 is generally directed at auto-discovering primary applications110, including their associated file systems and primary storage, andidentifying each application-specific disk image (e.g., 450, 550, 650,etc.) in primary storage.

At block 802, enhanced data agent 242 initiates communications with oneor more computing devices in system 200/300, e.g., based on networkconfiguration information available from storage manager 240.

At block 804, enhanced data agent 242 identifies computing platformshosting one or more applications 110, e.g., physical computing devices,virtual machines, and/or Containers

At block 806, enhanced data agent 242 identifies one or more primaryapplications 110 configured on the respective computing platform.

At block 808, which is a decision point, enhanced data agent 242determines whether a given identified primary application 110 has beentargeted for Live Synchronization? (e.g., via storage manager 240 and/orEDA 242 configuration). If not, the present primary application 110 willnot be Live Synched and control passes back to block 806 to identifyother primary application 110. If yes, control passes to block 810.

At block 810, which is a decision point, enhanced data agent 242determines whether the identified primary application 110 comprises anative connector and/or API (e.g., 430). The determination is based onnative intelligence built into enhanced data agent 242 and/or byquerying storage manager 240. If yes, control passes to block 814,otherwise control passes to block 812.

At block 812, enhanced data agent 242 pushes a functional moduledesignated an “application utility” (e.g., 570, 670) to the computingplatform hosting the primary application 110 to be installed thereon(e.g., on host 202) for communicating between EDA 242 and application110.

At block 814, enhanced data agent 242 uses a native connector/API 430 orinstalled application utility 570/670 to discover the primaryapplication's associated file system 111 and primary storageconfiguration (e.g., storage device 104, volume 1, volume 2), andidentify and locate the application-specific disk image (e.g., 450, 550,etc.).

At block 816, enhanced data agent 242 reports the auto-discoveredapplication-specific information (from the preceding block) to storagemanager 240 and/or retains the information in EDA 242.

FIG. 8B depicts some salient sub-operations of block 712 in method 700.Block 712 is generally directed at tracking changed data blocksgenerated by each application 110 targeted for Live Synchronization.

At block 842, which is a decision point, enhanced data agent 242determines whether the identified application 110 comprises a nativeutility for tracking changed blocks (e.g., 680), such as a log orjournal or like functionality. This determination is based onintelligence available in enhanced data agent 242. If yes, controlpasses to block 846, otherwise control passes to block 844.

At block 844, enhanced data agent 242 pushes an application-specific(specific to the targeted application 110) block change filter (e.g.,440, 540) to be installed and activated on the computing platformhosting the primary application (e.g., to 202).

At block 846, enhanced data agent 242 establishes communications withthe installed block change filter 440/540 (from the preceding block) orwith a native changed-block tracker 680 that is available in thetargeted application 110 or its associated file system 111.

At block 848, communications are (optionally) established between amedia agent 144 designated to back up/replicate the changed blocks forthe present primary application 110 and the native changed-block tracker680 or installed block change filter 440/540. This communication path isnot required in all embodiments.

At block 850, the native changed-block tracker 680 or installed blockchange filter 440/540 monitors the primary application's writeoperations.

At block 852, the native changed-block tracker 680 or installed blockchange filter 440/540 keeps track of changed data blocks over time,e.g., preparing point-in time changed-block maps for creatingincremental backups and recovery points and/or packaging data blocks fortransmission in replication operations. The changed data blocks are orwill be transmitted to enhanced data agent 242, ultimately resulting inincremental backups stored at intermediary secondary storage 108 or elsebeing continuously replicated to the standby/failover copy of the diskimage.

FIG. 9A depicts some salient sub-operations of block 714 in method 700.Block 714 is generally directed at taking incremental backups andrestoring them from an intermediate secondary storage to the standbycopy of the disk image (e.g., 460, etc.)

At block 902, enhanced data agent 242 receives from storage manager 240timing instructions and/or instructions to perform an incremental backupof targeted primary application 110, i.e., its disk image, e.g., 450.

At block 904, enhanced data agent 242 periodically (e.g., hourly) or ondetecting a certain amount of changed data blocks, uses thecorresponding connector for the targeted application (e.g., 411, 412,611) to reach out to and quiesce the application 110 for backup.

At block 906, enhanced data agent 242 receives changed data blocks (orpointers thereto or other indicators of changed data blocks) frominstalled application-specific block change filter 440/540 or fromnative block change tracker 680.

At block 908, enhanced data agent 242 performs an incremental backupcapturing changed data blocks since the preceding backup—using a mediaagent 144 assigned to store the incremental backup to intermediarystorage device 108. This incremental backup may be designated apoint-in-time recovery point to be used for restoring the primaryapplication 110 or the synchronized application 110S to an earlier knowngood point-in-time if need be.

At block 910, enhanced data agent 242 uses the corresponding connectorfor the targeted application (e.g., 411, 412, 611) to reach out to andun-quiesce the primary application 110 so that it may resume normaloperations.

At block 912, immediately after each incremental backup or periodically(e.g., daily), enhanced data agent 242 restore the incremental backupsaccumulated since the preceding restore, from intermediary storagedevice 108 to a standby copy of the disk image (e.g., 460, 560) at thestandby/failover computing platform. Control passes back to block 902for receiving further instructions, if any, from storage manager 240.

FIG. 9B depicts some salient sub-operations of block 716 in method 700.The present block is generally directed at performing block-levelcontinuous data replication, which mirrors changed data blocks in theprimary application's disk image to the standby copy of the disk image(e.g., 460, etc.)—without the need to restore from a backup copy.

At block 942, enhanced data agent 242 receives from storage manager 240instructions to perform block-level continuous data replication for thetargeted application 110.

At block 944, enhanced data agent 242 receives from storage manager 240and/or determines via its own resources one or more configurationparameters for the standby/failover destination storage device (e.g.,204, 504, 604, etc.) that is to store the standby copy of the diskimage.

At block 946, which is a decision point, enhanced data agent 242determines whether it has control over the standby/failover destinationstorage device (e.g., direct access to disk). If yes, control passes toblock 952, otherwise control passes to block 948.

At block 948, a second EDA (not shown in the present figures) isinstalled on the standby/failover destination host computing platform(e.g., 222, 522, 622, 1022, etc.). This second EDA is installed at thedestination host by storage manager 240, e.g., pushing the executablesoftware to the destination host. Alternatively, EDA 242 causes theinstall to happen, e.g., pushing the executable software to thedestination host.

At block 950, enhanced data agent 242 establishes communications betweenEDA 242 and the second EDA. This second EDA will act as an intermediaryrouting point for changed data blocks from EDA 242 that are destined forthe standby copy in the destination storage device. The second EDA actsas a portal for accessing the standby/failover storage device andwriting changed blocks thereto.

At block 952, which may follow after block 946 or 950, enhanced dataagent 242 receives changed data blocks from the primary host, e.g., frominstalled application-specific block change filter 440/540 or fromnative block change tracker 680 at the primary host. The respectiveblock tracker/filter monitors write operations performed by the targetedapplication 110 and detects changed blocks as they are written. Thechanged blocks are transmitted to EDA 242 on an ongoing basis; in someembodiments, the changed blocks are transmitted in closely spacedintervals that are effectively continuous.

At block 954, which is only performed in configurations where enhanceddata agent 242 lacks control over the destination storage device, i.e.,when a second EDA is operating at the standby/failover host, EDA 242transmits the changed data blocks to the second EDA at the destination.

At block 956, the changed data blocks are transmitted to the standbycopy (e.g., 460, 560, 660, and 1060) of the disk image on thedestination storage device, thereby keeping the standby copycontinuously updated without restoring from a backup copy. If a secondEDA is operating at the standby/failover host, the changed data blocksare transmitted to and the updating of the standby copy is performed bythe second EDA, using changed data blocks received from EDA 242. If EDA242 has control over the standby/failover storage device (e.g., directaccess to the disk), the changed data blocks are transmitted to and theupdating of the standby copy is performed by the EDA 242, using changeddata blocks received from the primary host.

FIG. 10 is a block diagram illustrating some salient portions of system200 or 300 for application-level Live Synchronization depicting LiveSynchronization of co-resident applications to disparate standbydestinations and further depicting selectively synchronizing someapplications and not others among the co-resident applications.Co-resident applications can be separately Live Synched as neededindependently of each other, such that co-resident primary applications110-1 and 110-k are dispersed to different and distinct standby/failoverdestinations 222 and 1022 respectively. Vice-versa, previously separatedapplications can be Live Synchronized to the same standby/failoverdestination (not shown). Furthermore, in the present figure, application110-2 is not selected for Live Synchronization at all, although it maybe backed up and protected in traditional ways.

Importantly, the illustrative systems can support cross-platform LiveSynchronization, such that the source/host and destination/standbycomputing platforms can be of different types and technologies, e.g.,from physical server to virtual machine and vice-versa, from one type ofvirtualized environment to another, from one type of container toanother, etc.

In some embodiments, “Application-Specific Live Sync” further includesone or more of the features below, without limitation:

-   -   Auto/Manual failover. Manual failover: administrators can        schedule failover of selected primary applications 110. This        type of failover performs the latest incremental backup and/or        replicates the latest changes to the standby/failover site and        performs application shutdown on the source and activates the        synchronized application 110S. Auto failover: Failover will be        initiated automatically when the primary site is dead due to        disaster or outage. This approach activates the failover site        and synchronized application 110S and disables further backups        of primary application 110 and breaks replication from source to        destination. In both scenarios, the system thereafter operates        the failover computing environment as the production environment        until such time as the original production environment can be        re-activated and appropriately restored.    -   Test failover of selected synchronized application 110S. This        failover mode is used to validate the replication at the        failover site without switching the production environment away        from the primary. This failover type makes sure the synchronized        (failover) applications 110S boot up successfully and can        execute certain given scripts that execute on the primary        application 110. The test results may be reported to storage        manager 240, a system console, or another reporting platform.    -   Failover synchronized application boot sequence and grouping.        Administrators may set the boot order for synchronized        applications 110S to come online. Application dependencies may        be handled this way, so that a dependent application 110S will        boot up after another synchronized application 110S boots up        first.    -   Reverse sync and data protection configuration from standby to        primary (production). After Manual\Auto failover of applications        from primary (source production environment) to a        standby/failover site, the failover can be the production site        for a temporary time period or for any duration. In that        situation, the illustrative system can protect the data of the        failover platform as this is the new production site, and        replicate data back to the primary site. This feature        automatically configures reverse replication and data protection        schedules.    -   Failback. After Manual\Auto failover as described above, this        feature helps to fail back to primary from the failover        environment. This provides options to keep the primary        environment as it was originally, or perhaps use different        storage, different server, etc.    -   Replication (block-level continuous data replication) to and        from cloud sites as the standby/failover destination.        Replication of applications to cloud platforms is automated,        e.g., to Azure, Amazon, VMWare vCloud, etc., without limitation,        and vice versa.    -   Multiple standby/failover sites for one primary application. In        some configurations, a given primary application 110 may be        synchronized to not just one, but to multiple standby/failover        destinations, any one of which can take over in case the primary        application 110 fails.

The preceding paragraphs provide a number of illustrative scenarios,which may operate in various combinations and permutations with eachother, without limitation.

In regard to the figures described herein, other embodiments arepossible within the scope of the present invention, such that theabove-recited components, steps, blocks, operations, and/ormessages/requests/queries/instructions are differently arranged,sequenced, sub-divided, organized, and/or combined. In some embodiments,a different component may initiate or execute a given operation and/or adifferent component may query, direct, or instruct another component toperform some of the recited functionality. Some of the functionalmodules (e.g., 410, 411, 412, 420, 620, etc.) are shown herein as adistinct sub-component to ease understanding of the present disclosure,however, alternative embodiments are also possible within the scope ofthe present invention wherein the disclosed functional module is layeredon existing code, combined with other functional modules, and/or onlyexists as a logical construct whose functionality is distributed throughone or more other functional modules of the parent component, e.g.,enhanced data agent 242. Likewise, native functionality depicted asmodules 430 and 680 may be implemented differently within the respectiveprimary application 110 and/or file system 111 than as depicted in thefigures herein.

Example Embodiments

Some example enumerated embodiments of the present invention are recitedin this section without limitation.

According to an illustrative embodiment, a method comprising:synchronizing a first application represented in a first disk image thatstores the first application's primary data to a standby version of thefirst application, wherein the first application executes on a firstcomputing platform in communication with the first disk image, which isstored in a first data storage device, wherein the first disk imagerepresents the first application and not a second application that alsoexecutes on the first computing platform, and wherein the standbyversion of the first application comprises a copy of the first diskimage which is stored in a second storage device associated with asecond computing platform that hosts the standby version of the firstapplication. The above-recited method wherein the synchronizingcomprises continuously replicating changed data blocks from the firstdisk image to the copy of the first disk image. The above-recited methodwherein the copy of the first disk image is continuously replicated fromchanged data blocks at the first disk image after an initial full backupof the first disk image. The above-recited method further comprising:booting up the standby version of the first application from the copy ofthe first disk image; and executing the standby version of the firstapplication on the second computing platform, based on the copy of thefirst disk image. The above-recited method further comprising: ondetecting a failure of the first application, booting up the standbyversion of the first application from the copy of the first disk image;and executing the standby version of the first application on the secondcomputing platform, based on the copy of the first disk image, whereinthe standby version of the first application executes instead of thefirst application. The above-recited method wherein after an initialfull backup of the first disk image, the copy of the first disk image isrepeatedly restored from incremental backups taken of the first diskimage which incremental backups comprise changed data blocks copied fromchanges at the first disk image. The above-recited method wherein thefirst application is selected for synchronization and further whereinthe second application that also executes on the first computingplatform is not selected for synchronization to a corresponding standbyversion, thereby selectively synchronizing some applications on thefirst computing platform and NOT other applications on the same firstcomputing platform.

The above-recited method wherein only a portion of the first disk imageis selected for synchronization such that the second copy of the firstdisk image represents only the selected portion of the first disk image,and wherein the selected portion is one of: a logical volume, a physicaldisk, a file, and a folder. The above-recited method wherein the firstcomputing platform is a physical computing device and wherein the secondcomputing platform is a virtual machine. The above-recited methodwherein the first computing platform is a virtual machine and whereinthe second computing platform is a physical computing device. Theabove-recited method wherein the first computing platform is a firsttype of virtual machine and wherein the second computing platform issecond type of virtual machine which is different from the first type ofvirtual machine. The above-recited method wherein the synchronizingcomprises: automatically discovering, by a data agent operating on athird computing platform that is distinct from the first computingplatform and the second computing platform, operational characteristicsof the first application, including identifying and locating the firstdisk image. The above-recited method wherein the synchronizingcomprises: causing to be installed on the first computing platform, by adata agent operating on a third computing platform that is distinct fromthe first computing platform and the second computing platform, anapplication-utility; causing the application-utility to establishcommunications with the first application and with the data agent; andautomatically discovering by the data agent, via theapplication-utility, operational characteristics of the firstapplication, including identifying and locating the first disk image.The above-recited method wherein the synchronizing comprises: causing tobe installed on the first computing platform, by a data agent operatingon a third computing platform that is distinct from the first computingplatform and the second computing platform, a changed-block filter;causing the changed-block filter intercept and transmit to the dataagent changed data blocks in the first disk image resulting from writeoperations performed by the first application; and using the changeddata blocks received from the changed-block filter to (a) repeatedlygenerate incremental backup copies of the first disk image, or (b)provide continuous data replication of the changed data blocks to thestandby copy of the first disk image. The above-recited method furthercomprising: identifying a second application that also executes on thefirst computing platform, wherein the second application is representedin a second disk image that stores the second application's primarydata, and wherein the second disk image represents the secondapplication and only the second application. The above-recited methodfurther comprising: synchronizing the second application to a standbyversion of the second application, wherein the standby version of thesecond application comprises a copy of the second disk image which isrestored to a third storage device associated with a third computingplatform that hosts the standby version of the second application, andwherein the third computing platform is distinct from the secondcomputing platform that hosts the standby version of the firstapplication. The above-recited method further comprising: on detecting afailure of the second application, booting up the standby version of thesecond application from the copy of the second disk image to execute inplace of the first application, wherein the standby version of thesecond application executes on the third computing platform; and therebysynchronizing co-resident applications to disparate standbydestinations. The above-recited method wherein the first application isprotected separately from any other application that also executes onthe same virtual machine as the first application. The above-recitedmethod wherein the first application and one or more second applicationsexecute on a first virtual machine; and wherein the first application isprotected separately from the one or more second applications.

According to another illustrative embodiment, a method comprising:synchronizing a first application represented in a first disk image thatstores the first application's primary data to a standby version of thefirst application, wherein the first application executes on a firstcomputing platform in communication with the first disk image, which isstored in a first data storage device, wherein the first disk imagerepresents the first application and not a second application that alsoexecutes on the first computing platform, and wherein the standbyversion of the first application comprises a copy of the first diskimage which is stored in a second storage device associated with asecond computing platform that hosts the standby version of the firstapplication; and wherein after an initial full backup of the first diskimage, the copy of the first disk image is repeatedly restored fromincremental backups taken of the first disk image which incrementalbackups comprise changed data blocks copied from changes at the firstdisk image. The above-recited method wherein the first application isprotected separately from any other application that also executes onthe same virtual machine as the first application. The above-recitedmethod wherein the first application and one or more second applicationsexecute on a first virtual machine; and wherein the first application isprotected separately from the one or more second applications.

Another illustrative embodiment comprises a computer-readable medium,excluding transitory propagating signals, storing instructions that,when executed by at least one secondary storage computing device, causethe secondary storage computing device to perform operations comprising:automatically discovering operational characteristics of a firstapplication, including identifying and locating a first disk image thatstores the first application's primary data and represents the firstapplication, wherein the first application executes on a first computingplatform in communication with the first disk image, and wherein thefirst computing platform is distinct from and in communication with thesecondary storage computing device. The above-recited computer-readablemedium further comprising: synchronizing the first applicationrepresented in the first disk image to a standby version of the firstapplication. The above-recited computer-readable medium wherein thestandby version of the first application comprises a copy of the firstdisk image which is stored in a second storage device associated with asecond computing platform that hosts the standby version of the firstapplication, and wherein the second computing platform is distinct fromthe first computing platform hosting the first application and is alsodistinct from the secondary storage computing device. The above-recitedcomputer-readable medium wherein the operations further comprise: ondetecting a failure of the first application, causing the standbyversion of the first application (a) to boot up from the copy of thefirst disk image, and (b) to execute instead of the first application,wherein the standby version of the first application executes on thesecond computing platform.

The above-recited computer-readable medium wherein the copy of the firstdisk image is continuously replicated from changed data blocks at thefirst disk image after an initial full backup of the first disk image.The above-recited computer-readable medium wherein after an initial fullbackup of the first disk image, the copy of the first disk image isrepeatedly restored from incremental backups taken of the first diskimage which incremental backups comprise changed data blocks copied fromchanges at the first disk image.

According to another illustrative embodiment, a computer-readablemedium, excluding transitory propagating signals, storing instructionsthat, when executed by at least one computing device in a storagemanagement system, cause the at least one computing device to performoperations comprising: synchronizing a first application represented ina first disk image that stores the first application's primary data to astandby version of the first application. The above-recitedcomputer-readable medium wherein the first application executes on afirst computing platform in communication with the first disk image. Theabove-recited computer-readable medium wherein the first disk imagerepresents the first application. The above-recited computer-readablemedium wherein the standby version of the first application comprises acopy of the first disk image which is stored in a second storage deviceassociated with a second computing platform that hosts the standbyversion of the first application. The above-recited computer-readablemedium further comprising: booting up the standby version of the firstapplication from the copy of the first disk image. The above-recitedcomputer-readable medium further comprising: executing the standbyversion of the first application on the second computing platform, basedon the copy of the first disk image.

In another embodiment, a system for synchronizing a first application ona first computing platform to a standby version of the application on asecond computing platform, may comprise: a first computing platformcomprising one or more first computing devices, wherein one of the oneor more first computing devices hosts the first application; a firstdata storage device, in communication with the first computing platform,wherein the first data storage device comprises a first disk image thatrepresents the first application and comprises the first application'sprimary data; a second computing platform comprising one or more secondcomputing devices, distinct from the first computing devices, whereinone of the one or more second computing devices hosts a standby versionof the first application; a second data storage device, in communicationwith the second computing platform, wherein the second data storagedevice comprises a copy of the first disk image; and a third computingdevice that hosts a data agent for continuously replicating changed datablocks from the first disk image to the copy of the first disk image,thereby synchronizing the first application to the standby version ofthe application.

The above-recited system further comprising a fourth computing devicethat hosts a storage manager for managing storage operations in thesystem, including managing of the continuously replicating changed datablocks; and wherein the data agent is configured to discover the firstapplication in response to a query received from the storage manager.The above-recited system wherein the data agent is configured to quiescethe first application before performing a backup of the first diskimage. The above-recited system wherein the data agent is configured to:quiesce the first application, and participate in generating a backupcopy of the first disk image. The above-recited system wherein the dataagent is configured to: quiesce the first application, participate ingenerating a backup copy of the first disk image, and participate inrestoring the backup copy of the first disk image as an initial versionof the copy of the first disk image stored in the second data storagedevice. The above-recited system wherein the standby version of thefirst application is configured to execute based on the copy of thefirst disk image stored in the second data storage device.

In yet another embodiment, a system for synchronizing a firstapplication on a first computing platform to a standby version of theapplication on a second computing platform may comprise: a firstcomputing platform comprising one or more first computing devices,wherein one of the one or more first computing devices hosts the firstapplication; a first data storage device, in communication with thefirst computing platform, wherein the first data storage devicecomprises a first disk image that represents the first application andcomprises the first application's primary data; a second computingplatform comprising one or more second computing devices, distinct fromthe first computing devices, wherein one of the one or more secondcomputing devices hosts a standby version of the first application; asecond data storage device, in communication with the second computingplatform, wherein the second data storage device comprises a copy of thefirst disk image; and a third computing device that hosts a data agentfor periodically generating a backup copy of the first disk image, andfurther for restoring the respective backup copy of the first disk imageto the copy of the first disk image stored in the second data storagedevice, thereby synchronizing the first application to the standbyversion of the application.

The above-recited system wherein the data agent is configured todiscover one or more operational characteristics of the firstapplication. The above-recited system wherein the data agent isconfigured to discover one or more operational characteristics of thefirst application, including identifying and locating the first diskimage. The above-recited system further comprising a fourth computingdevice that hosts a storage manager for managing storage operations inthe system, including managing the generating and restoring operations;and wherein the data agent is configured to discover one or moreoperational characteristics of the first application in response to aquery received from the storage manager. The above-recited systemwherein the data agent is configured to quiesce the first applicationbefore generating the backup copy of the first disk image. Theabove-recited system wherein the data agent is configured to: quiescethe first application, and participate in the generating of the backupcopy of the first disk image in conjunction with a media agent that alsoexecutes on the third computing device. The above-recited system whereinthe data agent is configured to: quiesce the first application,participate in the generating of the backup copy of the first disk imagein conjunction with a media agent that also executes on the thirdcomputing device, and participate in the restoring of the backup copy ofthe first disk image in conjunction with the media agent. Theabove-recited system wherein the standby version of the firstapplication is configured to execute based on the copy of the first diskimage stored in the second data storage device.

In another illustrative embodiment, a data agent executing on a firstcomputing platform for application synchronization executes a methodcomprising: initiating communications between the data agent and one orcomputing devices distinct from the first computing platform;identifying one or more second computing platforms that respectivelyhost one or more applications, wherein a second computing platformcomprises one of: a physical computing device, a virtual machine, and asoftware container; identifying a first of the one or more applications;if the first application has not been targeted for synchronization,identifying a second of the one or more applications; if the firstapplication has been targeted for synchronization, determining whetherthe first application comprises a native connector and/or applicationprogramming interface; if the first application does not comprise thenative connector and/or application programming interface, pushing anapplication-utility to the second computing platform that hosts thefirst application; communicating with one of: the native connector,application programming interface, and application-utility available onthe second computing platform that hosts the first application, todiscover the first application's associated file system and primarystorage configuration and to identify and locate the first application'sdisk image; and reporting the discovered, identified, and locatedinformation to a storage manager.

In another illustrative embodiment, a changed-block tracker executing ona first computing device that also hosts a first application targetedfor synchronization executes a method comprising: establishingcommunications between the changed-block tracker and a data agent thatexecutes on a second computing device; establishing communicationsbetween the changed-block tracker and a media agent that also executeson the second computing device; monitoring the first application's writeoperations to identify changed data blocks in a first disk image of thefirst application stored in a first data storage device accessible tothe first application; and tracking the identified changed data blocks.The above-recited method wherein the changed-block tracker uses theidentified changed data blocks to generate successive point-in-timechanged-block maps for incremental backup copies of the first diskimage. The above-recited method wherein the changed-block trackertransmits the identified changed data blocks to a copy of the first diskimage on a second data storage device.

In yet another example embodiment, a data agent executing on a firstcomputing platform for application synchronization executes a methodcomprising: receiving from a storage manager instructions to perform anincremental backup; periodically or on detecting that a number ofchanged data blocks exceeds a threshold, quiescing a first applicationthat executes on a first computing device that is distinct from thefirst computing platform; receiving a set of changed data blocks from achanged-block tracker on the first computing device; performing anincremental backup that captures the set of changed data blocks since apreceding backup operation, wherein a media agent stores the set ofchanged data blocks to an intermediary data storage device; un-quiescingthe first application; and restoring the set of changed data blocks fromthe intermediary data storage device to a standby copy of the firstapplication on a second computing device configured as a standbydestination for the first application.

In another illustrative embodiment, a data agent executing on a firstcomputing platform for application synchronization executes a methodcomprising: receiving instructions from a storage manager to performblock-level continuous data replication for a first disk image thatrepresents a first application and comprises the first application'sprimary data; receiving changed data blocks from a changed-block trackerco-resident with the first application; and applying the changed datablocks to a standby copy of the first disk image, thereby keeping thestandby copy continuously synchronized with the first disk image withoutusing a restore operation for keeping the standby copy continuouslysynchronized with the first disk image.

In other embodiments, a system or systems may operate according to oneor more of the methods and/or computer-readable media recited in thepreceding paragraphs. In yet other embodiments, a method or methods mayoperate according to one or more of the systems and/or computer-readablemedia recited in the preceding paragraphs. In yet more embodiments, acomputer-readable medium or media, excluding transitory propagatingsignals, may cause one or more computing devices having one or moreprocessors and non-transitory computer-readable memory to operateaccording to one or more of the systems and/or methods recited in thepreceding paragraphs. In yet other embodiments, system, methods, and/orcomputer-readable media may operate according to the systems andflowcharts depicted in FIGS. 2-10 and according to the accompanyingparagraphs, whether taken in whole or in part, and in any combinationthereof, without limitation.

Terminology

Conditional Language, Such as, Among Others, “can,” “could,” “Might,” or“May,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense, i.e., in the sense of “including, but notlimited to.” As used herein, the terms “connected,” “coupled,” or anyvariant thereof means any connection or coupling, either direct orindirect, between two or more elements; the coupling or connectionbetween the elements can be physical, logical, or a combination thereof.Additionally, the words “herein,” “above,” “below,” and words of similarimport, when used in this application, refer to this application as awhole and not to any particular portions of this application. Where thecontext permits, words using the singular or plural number may alsoinclude the plural or singular number respectively. The word “or” inreference to a list of two or more items, covers all of the followinginterpretations of the word: any one of the items in the list, all ofthe items in the list, and any combination of the items in the list.Likewise the term “and/or” in reference to a list of two or more items,covers all of the following interpretations of the word: any one of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

In some embodiments, certain operations, acts, events, or functions ofany of the algorithms described herein can be performed in a differentsequence, can be added, merged, or left out altogether (e.g., not allare necessary for the practice of the algorithms). In certainembodiments, operations, acts, functions, or events can be performedconcurrently, e.g., through multi-threaded processing, interruptprocessing, or multiple processors or processor cores or on otherparallel architectures, rather than sequentially.

Systems and modules described herein may comprise software, firmware,hardware, or any combination(s) of software, firmware, or hardwaresuitable for the purposes described. Software and other modules mayreside and execute on servers, workstations, personal computers,computerized tablets, PDAs, and other computing devices suitable for thepurposes described herein. Software and other modules may be accessiblevia local computer memory, via a network, via a browser, or via othermeans suitable for the purposes described herein. Data structuresdescribed herein may comprise computer files, variables, programmingarrays, programming structures, or any electronic information storageschemes or methods, or any combinations thereof, suitable for thepurposes described herein. User interface elements described herein maycomprise elements from graphical user interfaces, interactive voiceresponse, command line interfaces, and other suitable interfaces.

Further, processing of the various components of the illustrated systemscan be distributed across multiple machines, networks, and othercomputing resources. Two or more components of a system can be combinedinto fewer components. Various components of the illustrated systems canbe implemented in one or more virtual machines, rather than in dedicatedcomputer hardware systems and/or computing devices. Likewise, the datarepositories shown can represent physical and/or logical data storage,including, e.g., storage area networks or other distributed storagesystems. Moreover, in some embodiments the connections between thecomponents shown represent possible paths of data flow, rather thanactual connections between hardware. While some examples of possibleconnections are shown, any of the subset of the components shown cancommunicate with any other subset of components in variousimplementations.

Embodiments are also described above with reference to flow chartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products. Each block of the flow chart illustrationsand/or block diagrams, and combinations of blocks in the flow chartillustrations and/or block diagrams, may be implemented by computerprogram instructions. Such instructions may be provided to a processorof a general purpose computer, special purpose computer,specially-equipped computer (e.g., comprising a high-performancedatabase server, a graphics subsystem, etc.) or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor(s) of the computer or other programmabledata processing apparatus, create means for implementing the actsspecified in the flow chart and/or block diagram block or blocks. Thesecomputer program instructions may also be stored in a non-transitorycomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flow chart and/or blockdiagram block or blocks. The computer program instructions may also beloaded to a computing device or other programmable data processingapparatus to cause operations to be performed on the computing device orother programmable apparatus to produce a computer implemented processsuch that the instructions which execute on the computing device orother programmable apparatus provide steps for implementing the actsspecified in the flow chart and/or block diagram block or blocks.

Any patents and applications and other references noted above, includingany that may be listed in accompanying filing papers, are incorporatedherein by reference. Aspects of the invention can be modified, ifnecessary, to employ the systems, functions, and concepts of the variousreferences described above to provide yet further implementations of theinvention. These and other changes can be made to the invention in lightof the above Detailed Description. While the above description describescertain examples of the invention, and describes the best modecontemplated, no matter how detailed the above appears in text, theinvention can be practiced in many ways. Details of the system may varyconsiderably in its specific implementation, while still beingencompassed by the invention disclosed herein. As noted above,particular terminology used when describing certain features or aspectsof the invention should not be taken to imply that the terminology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the invention with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the invention to the specific examplesdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe invention encompasses not only the disclosed examples, but also allequivalent ways of practicing or implementing the invention under theclaims.

To reduce the number of claims, certain aspects of the invention arepresented below in certain claim forms, but the applicant contemplatesother aspects of the invention in any number of claim forms. Forexample, while only one aspect of the invention is recited as ameans-plus-function claim under 35 U.S.C sec. 112(f) (AIA), otheraspects may likewise be embodied as a means-plus-function claim, or inother forms, such as being embodied in a computer-readable medium. Anyclaims intended to be treated under 35 U.S.C. §112(f) will begin withthe words “means for,” but use of the term “for” in any other context isnot intended to invoke treatment under 35 U.S.C. §112(f). Accordingly,the applicant reserves the right to pursue additional claims afterfiling this application, in either this application or in a continuingapplication.

What is claimed is:
 1. A method comprising: synchronizing a firstapplication, which is represented in a first disk image that stores thefirst application's primary data, to a standby version of the firstapplication, wherein the first application executes on a first computingplatform in communication with the first disk image, which is stored ina first data storage device, wherein the first disk image represents thefirst application and not a second application that also executes on thefirst computing platform, and wherein the standby version of the firstapplication comprises a copy of the first disk image which is stored ina second storage device associated with a second computing platform thathosts the standby version of the first application; and wherein thesynchronizing comprises continuously replicating changed data blocksfrom the first disk image to the copy of the first disk image.
 2. Themethod of claim 1 wherein the copy of the first disk image iscontinuously replicated from changed data blocks at the first disk imageafter an initial backup of the first disk image.
 3. The method of claim1 further comprising: booting up the standby version of the firstapplication from the copy of the first disk image; and executing thestandby version of the first application on the second computingplatform, based on the copy of the first disk image.
 4. The method ofclaim 1 further comprising: on detecting a failure of the firstapplication, booting up the standby version of the first applicationfrom the copy of the first disk image; and executing the standby versionof the first application on the second computing platform, based on thecopy of the first disk image, wherein the standby version of the firstapplication executes instead of the first application.
 5. The method ofclaim 1 wherein after an initial backup of the first disk image, thecopy of the first disk image is repeatedly restored from incrementalbackups taken of the first disk image which incremental backups comprisechanged data blocks copied from changes at the first disk image.
 6. Themethod of claim 1 wherein the first application is selected forsynchronization and further wherein the second application that alsoexecutes on the first computing platform is not selected forsynchronization to a corresponding standby version, thereby selectivelysynchronizing some applications on the first computing platform and notother applications on the same first computing platform.
 7. The methodof claim 1 wherein only a portion of the first disk image is selectedfor synchronization such that the second copy of the first disk imagerepresents only the selected portion of the first disk image, andwherein the selected portion is one of: a logical volume, a physicaldisk, a file, and a folder.
 8. The method of claim 1 wherein the firstcomputing platform is a physical computing device and wherein the secondcomputing platform is a virtual machine.
 9. The method of claim 1wherein the first computing platform is a virtual machine and whereinthe second computing platform is a physical computing device.
 10. Themethod of claim 1 wherein the first computing platform is a first typeof virtual machine and wherein the second computing platform is secondtype of virtual machine which is different from the first type ofvirtual machine.
 11. The method of claim 1 wherein the synchronizingcomprises: automatically discovering, by a data agent operating on athird computing platform that is distinct from the first computingplatform and the second computing platform, operational characteristicsof the first application, including identifying and locating the firstdisk image.
 12. The method of claim 1 wherein the synchronizingcomprises: causing to be installed on the first computing platform, by adata agent operating on a third computing platform that is distinct fromthe first computing platform and the second computing platform, anapplication-utility; causing the application utility to establishcommunications with the first application and with the data agent; andautomatically discovering by the data agent, via the applicationutility, operational characteristics of the first application, includingidentifying and locating the first disk image.
 13. The method of claim 1wherein the synchronizing comprises: causing to be installed on thefirst computing platform, by a data agent operating on a third computingplatform that is distinct from the first computing platform and thesecond computing platform, a changed-block filter; causing thechanged-block filter intercept and transmit to the data agent changeddata blocks in the first disk image resulting from write operationsperformed by the first application; and using the changed data blocksreceived from the changed-block filter to (a) repeatedly generateincremental backup copies of the first disk image, or (b) providecontinuous data replication of the changed data blocks to the standbycopy of the first disk image.
 14. The method of claim 1 furthercomprising: identifying a second application that also executes on thefirst computing platform, wherein the second application is representedin a second disk image that stores the second application's primarydata, and wherein the second disk image represents the secondapplication and only the second application; synchronizing the secondapplication to a standby version of the second application, wherein thestandby version of the second application comprises a copy of the seconddisk image which is restored to a third storage device associated with athird computing platform that hosts the standby version of the secondapplication, and wherein the third computing platform is distinct fromthe second computing platform that hosts the standby version of thefirst application; on detecting a failure of the second application,booting up the standby version of the second application from the copyof the second disk image to execute in place of the first application,wherein the standby version of the second application executes on thethird computing platform; thereby synchronizing co-resident applicationsto disparate standby destinations.
 15. A computer-readable medium,excluding transitory propagating signals, storing instructions that,when executed by at least one secondary storage computing device, causethe secondary storage computing device to perform operations comprising:automatically discovering operational characteristics of a firstapplication, including identifying and locating a first disk image thatstores the first application's primary data and represents the firstapplication, wherein the first application executes on a first computingplatform in communication with the first disk image, and wherein thefirst computing platform is distinct from and in communication with thesecondary storage computing device; synchronizing the first applicationrepresented in the first disk image to a standby version of the firstapplication, wherein the standby version of the first applicationcomprises a copy of the first disk image which is stored in a secondstorage device associated with a second computing platform that hoststhe standby version of the first application, wherein the secondcomputing platform is distinct from the first computing platform hostingthe first application and is also distinct from the secondary storagecomputing device, and wherein the copy of the first disk image iscontinuously replicated from changed data blocks at the first disk imageafter an initial backup of the first disk image.
 16. Thecomputer-readable medium of claim 15 wherein the operations furthercomprise: on detecting a failure of the first application, causing thestandby version of the first application (a) to boot up from the copy ofthe first disk image, and (b) to execute instead of the firstapplication, wherein the standby version of the first applicationexecutes on the second computing platform.
 17. The computer-readablemedium of claim 15 wherein the copy of the first disk image iscontinuously replicated from changed data blocks at the first disk imageafter an initial backup of the first disk image.
 18. Thecomputer-readable medium of claim 15 wherein after an initial backup ofthe first disk image, the copy of the first disk image is repeatedlyrestored from incremental backups taken of the first disk image whichincremental backups comprise changed data blocks copied from changes atthe first disk image.
 19. A computer-readable medium, excludingtransitory propagating signals, storing instructions that, when executedby at least one computing device in a storage management system, causethe at least one computing device to perform operations comprising:synchronizing a first application represented in a first disk image thatstores the first application's primary data to a standby version of thefirst application, wherein the first application executes on a firstcomputing platform in communication with the first disk image, whereinthe first disk image represents the first application, and wherein thestandby version of the first application comprises a copy of the firstdisk image which is stored in a second storage device associated with asecond computing platform that hosts the standby version of the firstapplication; booting up the standby version of the first applicationfrom the copy of the first disk image; and executing the standby versionof the first application on the second computing platform, based on thecopy of the first disk image.